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                           <rdf:li><rdf:Description xmpDM:name="Electronic Codebook (ECB) Mode How to encode multiple blocks of a long message? Each block is encoded independently of the" xmpDM:startTime="0" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="others Ci = EK(Pi) Each block is substituted like a codebook, hence name." xmpDM:startTime="0" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Ref: http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation" xmpDM:startTime="0" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="" xmpDM:startTime="0" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="ECB Limitations Using the same key on multiple blocks makes it easier to break Identical Plaintext Identical Ciphertext Does not" xmpDM:startTime="23900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="change pattern: Original ECB Better NIST SP 800-38A defines 5 modes that can be used with any block cipher Ref:" xmpDM:startTime="23900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="http://en.wikipedia.org/wiki/Modes_of_operation" xmpDM:startTime="23900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="" xmpDM:startTime="23900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cipher Block Chaining (CBC) Add random numbers before encrypting Previous cipher blocks is chained with current plaintext block Use an" xmpDM:startTime="95533" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Initial Vector (IV) to start process Ci = EK(Pi XOR Ci-1) C-1 = IV" xmpDM:startTime="95533" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="ECB Limitations Using the same key on multiple blocks makes it easier to break Identical Plaintext Identical Ciphertext Does not" xmpDM:startTime="196300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="change pattern: Original ECB Better NIST SP 800-38A defines 5 modes that can be used with any block cipher Ref:" xmpDM:startTime="196300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="http://en.wikipedia.org/wiki/Modes_of_operation" xmpDM:startTime="196300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="" xmpDM:startTime="196300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cipher Block Chaining (CBC) Add random numbers before encrypting Previous cipher blocks is chained with current plaintext block Use an" xmpDM:startTime="209567" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Initial Vector (IV) to start process Ci = EK(Pi XOR Ci-1) C-1 = IV" xmpDM:startTime="209567" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of CBC Any change to a block affects all following ciphertext blocks Need Initialization Vector (IV) Must" xmpDM:startTime="222800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="be known to sender &amp; receiver If sent in clear, attacker can change bits of first block, and change IV" xmpDM:startTime="222800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="to compensate Hence IV must either be a fixed value, e.g.," xmpDM:startTime="222800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="in Electronic Funds Transfers at Point of Sale (EFTPOS) Or must be sent encrypted in ECB mode before rest of" xmpDM:startTime="222800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="message Sequential implementation." xmpDM:startTime="222800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cannot be parallelized." xmpDM:startTime="222800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="" xmpDM:startTime="222800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cipher Block Chaining (CBC) Add random numbers before encrypting Previous cipher blocks is chained with current plaintext block Use an" xmpDM:startTime="249700" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Initial Vector (IV) to start process Ci = EK(Pi XOR Ci-1) C-1 = IV" xmpDM:startTime="249700" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of CBC Any change to a block affects all following ciphertext blocks Need Initialization Vector (IV) Must" xmpDM:startTime="294900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="be known to sender &amp; receiver If sent in clear, attacker can change bits of first block, and change IV" xmpDM:startTime="294900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="to compensate Hence IV must either be a fixed value, e.g.," xmpDM:startTime="294900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="in Electronic Funds Transfers at Point of Sale (EFTPOS) Or must be sent encrypted in ECB mode before rest of" xmpDM:startTime="294900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="message Sequential implementation." xmpDM:startTime="294900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cannot be parallelized." xmpDM:startTime="294900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="" xmpDM:startTime="294900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cipher Block Chaining (CBC) Add random numbers before encrypting Previous cipher blocks is chained with current plaintext block Use an" xmpDM:startTime="320567" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Initial Vector (IV) to start process Ci = EK(Pi XOR Ci-1) C-1 = IV" xmpDM:startTime="320567" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of CBC Any change to a block affects all following ciphertext blocks Need Initialization Vector (IV) Must" xmpDM:startTime="334667" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="be known to sender &amp; receiver If sent in clear, attacker can change bits of first block, and change IV" xmpDM:startTime="334667" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="to compensate Hence IV must either be a fixed value, e.g.," xmpDM:startTime="334667" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="in Electronic Funds Transfers at Point of Sale (EFTPOS) Or must be sent encrypted in ECB mode before rest of" xmpDM:startTime="334667" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="message Sequential implementation." xmpDM:startTime="334667" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cannot be parallelized." xmpDM:startTime="334667" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="" xmpDM:startTime="334667" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Message Padding Last block may be shorter than others Þ Pad Pad with count of pad size [ANSI X.923]" xmpDM:startTime="372167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="E.g.," xmpDM:startTime="372167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="[ b1 b2 b3 0 0 0 0 5] = 3 data, 5 pad w 1 count byte A 1" xmpDM:startTime="372167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="bit followed by 0 bits [ISO/IEC 9797-1] Any known byte value followed by zeros, e.g.," xmpDM:startTime="372167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="80-00… Random data followed by count [ISO 10126] E.g.," xmpDM:startTime="372167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="[b1 b2 b3 84 67 87 56 05] Each byte indicates the number of padded bytes [PKCS] E.g.," xmpDM:startTime="372167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="[b1 b2 b3 05 05 05 05 05] Self-Describing Padding [RFC1570] Each pad octet contains its index starting with 1" xmpDM:startTime="372167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="E.g.," xmpDM:startTime="372167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="[b1 b2 b3 1 2 3 4 5] Ref: http://en.wikipedia.org/wiki/Padding_%28cryptography%29" xmpDM:startTime="372167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="" xmpDM:startTime="372167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cipher Text Stealing (CTS) Alternative to padding which adds extra bytes." xmpDM:startTime="860767" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Last 2 blocks are specially coded Tail bits of (n-1)st encoded block are added to nth block and order of" xmpDM:startTime="860767" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="transmission of the two blocks is interchanged." xmpDM:startTime="860767" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Þ Size of ciphertext is same as plane text." xmpDM:startTime="860767" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="No extra bytes." xmpDM:startTime="860767" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="" xmpDM:startTime="860767" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Stream Modes of Operation Use block cipher as some form of pseudo-random number generator The random number bits are then" xmpDM:startTime="1116000" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="XOR’ed with the message (as in stream cipher) Convert block cipher into stream cipher Cipher feedback (CFB) mode Output feedback" xmpDM:startTime="1116000" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(OFB) mode Counter (CTR) mode" xmpDM:startTime="1116000" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cipher Feedback (CFB) Message is added to the output of the block cipher Result is feed back for next stage" xmpDM:startTime="1269900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(hence name) Standard allows any number of bit (1, 8, 64 or 128 etc) to be feed back, denoted CFB-1," xmpDM:startTime="1269900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="CFB-8, CFB-64, CFB-128 etc Most efficient to use all bits in block (64 or 128) Ci = Pi XOR EK(Ci-1)" xmpDM:startTime="1269900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="C-1 = IV Errors propagate for several blocks after the error" xmpDM:startTime="1269900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Output Feedback (OFB) Output of the cipher is feed back (hence name) Feedback is independent of message Can be computed" xmpDM:startTime="1668067" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="in advance Oi = EK(Oi-1) Ci = Pi XOR Oi O-1 = IV" xmpDM:startTime="1668067" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cipher Feedback (CFB) Message is added to the output of the block cipher Result is feed back for next stage" xmpDM:startTime="1719400" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(hence name) Standard allows any number of bit (1, 8, 64 or 128 etc) to be feed back, denoted CFB-1," xmpDM:startTime="1719400" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="CFB-8, CFB-64, CFB-128 etc Most efficient to use all bits in block (64 or 128) Ci = Pi XOR EK(Ci-1)" xmpDM:startTime="1719400" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="C-1 = IV Errors propagate for several blocks after the error" xmpDM:startTime="1719400" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Output Feedback (OFB) Output of the cipher is feed back (hence name) Feedback is independent of message Can be computed" xmpDM:startTime="1722233" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="in advance Oi = EK(Oi-1) Ci = Pi XOR Oi O-1 = IV" xmpDM:startTime="1722233" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cipher Feedback (CFB) Message is added to the output of the block cipher Result is feed back for next stage" xmpDM:startTime="1793833" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(hence name) Standard allows any number of bit (1, 8, 64 or 128 etc) to be feed back, denoted CFB-1," xmpDM:startTime="1793833" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="CFB-8, CFB-64, CFB-128 etc Most efficient to use all bits in block (64 or 128) Ci = Pi XOR EK(Ci-1)" xmpDM:startTime="1793833" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="C-1 = IV Errors propagate for several blocks after the error" xmpDM:startTime="1793833" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Stream Modes of Operation Use block cipher as some form of pseudo-random number generator The random number bits are then" xmpDM:startTime="1811967" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="XOR’ed with the message (as in stream cipher) Convert block cipher into stream cipher Cipher feedback (CFB) mode Output feedback" xmpDM:startTime="1811967" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(OFB) mode Counter (CTR) mode" xmpDM:startTime="1811967" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cipher Text Stealing (CTS) Alternative to padding which adds extra bytes." xmpDM:startTime="1812433" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Last 2 blocks are specially coded Tail bits of (n-1)st encoded block are added to nth block and order of" xmpDM:startTime="1812433" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="transmission of the two blocks is interchanged." xmpDM:startTime="1812433" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Þ Size of ciphertext is same as plane text." xmpDM:startTime="1812433" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="No extra bytes." xmpDM:startTime="1812433" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="" xmpDM:startTime="1812433" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Message Padding Last block may be shorter than others Þ Pad Pad with count of pad size [ANSI X.923]" xmpDM:startTime="1812633" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="E.g.," xmpDM:startTime="1812633" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="[ b1 b2 b3 0 0 0 0 5] = 3 data, 5 pad w 1 count byte A 1" xmpDM:startTime="1812633" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="bit followed by 0 bits [ISO/IEC 9797-1] Any known byte value followed by zeros, e.g.," xmpDM:startTime="1812633" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="80-00… Random data followed by count [ISO 10126] E.g.," xmpDM:startTime="1812633" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="[b1 b2 b3 84 67 87 56 05] Each byte indicates the number of padded bytes [PKCS] E.g.," xmpDM:startTime="1812633" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="[b1 b2 b3 05 05 05 05 05] Self-Describing Padding [RFC1570] Each pad octet contains its index starting with 1" xmpDM:startTime="1812633" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="E.g.," xmpDM:startTime="1812633" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="[b1 b2 b3 1 2 3 4 5] Ref: http://en.wikipedia.org/wiki/Padding_%28cryptography%29" xmpDM:startTime="1812633" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="" xmpDM:startTime="1812633" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of CBC Any change to a block affects all following ciphertext blocks Need Initialization Vector (IV) Must" xmpDM:startTime="1812800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="be known to sender &amp; receiver If sent in clear, attacker can change bits of first block, and change IV" xmpDM:startTime="1812800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="to compensate Hence IV must either be a fixed value, e.g.," xmpDM:startTime="1812800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="in Electronic Funds Transfers at Point of Sale (EFTPOS) Or must be sent encrypted in ECB mode before rest of" xmpDM:startTime="1812800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="message Sequential implementation." xmpDM:startTime="1812800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cannot be parallelized." xmpDM:startTime="1812800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="" xmpDM:startTime="1812800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cipher Block Chaining (CBC) Add random numbers before encrypting Previous cipher blocks is chained with current plaintext block Use an" xmpDM:startTime="1813000" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Initial Vector (IV) to start process Ci = EK(Pi XOR Ci-1) C-1 = IV" xmpDM:startTime="1813000" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of CBC Any change to a block affects all following ciphertext blocks Need Initialization Vector (IV) Must" xmpDM:startTime="1858500" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="be known to sender &amp; receiver If sent in clear, attacker can change bits of first block, and change IV" xmpDM:startTime="1858500" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="to compensate Hence IV must either be a fixed value, e.g.," xmpDM:startTime="1858500" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="in Electronic Funds Transfers at Point of Sale (EFTPOS) Or must be sent encrypted in ECB mode before rest of" xmpDM:startTime="1858500" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="message Sequential implementation." xmpDM:startTime="1858500" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cannot be parallelized." xmpDM:startTime="1858500" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="" xmpDM:startTime="1858500" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Message Padding Last block may be shorter than others Þ Pad Pad with count of pad size [ANSI X.923]" xmpDM:startTime="1859100" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="E.g.," xmpDM:startTime="1859100" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="[ b1 b2 b3 0 0 0 0 5] = 3 data, 5 pad w 1 count byte A 1" xmpDM:startTime="1859100" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="bit followed by 0 bits [ISO/IEC 9797-1] Any known byte value followed by zeros, e.g.," xmpDM:startTime="1859100" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="80-00… Random data followed by count [ISO 10126] E.g.," xmpDM:startTime="1859100" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="[b1 b2 b3 84 67 87 56 05] Each byte indicates the number of padded bytes [PKCS] E.g.," xmpDM:startTime="1859100" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="[b1 b2 b3 05 05 05 05 05] Self-Describing Padding [RFC1570] Each pad octet contains its index starting with 1" xmpDM:startTime="1859100" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="E.g.," xmpDM:startTime="1859100" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="[b1 b2 b3 1 2 3 4 5] Ref: http://en.wikipedia.org/wiki/Padding_%28cryptography%29" xmpDM:startTime="1859100" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="" xmpDM:startTime="1859100" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cipher Text Stealing (CTS) Alternative to padding which adds extra bytes." xmpDM:startTime="1859533" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Last 2 blocks are specially coded Tail bits of (n-1)st encoded block are added to nth block and order of" xmpDM:startTime="1859533" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="transmission of the two blocks is interchanged." xmpDM:startTime="1859533" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Þ Size of ciphertext is same as plane text." xmpDM:startTime="1859533" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="No extra bytes." xmpDM:startTime="1859533" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="" xmpDM:startTime="1859533" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Stream Modes of Operation Use block cipher as some form of pseudo-random number generator The random number bits are then" xmpDM:startTime="1860000" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="XOR’ed with the message (as in stream cipher) Convert block cipher into stream cipher Cipher feedback (CFB) mode Output feedback" xmpDM:startTime="1860000" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(OFB) mode Counter (CTR) mode" xmpDM:startTime="1860000" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cipher Feedback (CFB) Message is added to the output of the block cipher Result is feed back for next stage" xmpDM:startTime="1860600" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(hence name) Standard allows any number of bit (1, 8, 64 or 128 etc) to be feed back, denoted CFB-1," xmpDM:startTime="1860600" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="CFB-8, CFB-64, CFB-128 etc Most efficient to use all bits in block (64 or 128) Ci = Pi XOR EK(Ci-1)" xmpDM:startTime="1860600" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="C-1 = IV Errors propagate for several blocks after the error" xmpDM:startTime="1860600" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Output Feedback (OFB) Output of the cipher is feed back (hence name) Feedback is independent of message Can be computed" xmpDM:startTime="1861300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="in advance Oi = EK(Oi-1) Ci = Pi XOR Oi O-1 = IV" xmpDM:startTime="1861300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cipher Feedback (CFB) Message is added to the output of the block cipher Result is feed back for next stage" xmpDM:startTime="1913933" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(hence name) Standard allows any number of bit (1, 8, 64 or 128 etc) to be feed back, denoted CFB-1," xmpDM:startTime="1913933" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="CFB-8, CFB-64, CFB-128 etc Most efficient to use all bits in block (64 or 128) Ci = Pi XOR EK(Ci-1)" xmpDM:startTime="1913933" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="C-1 = IV Errors propagate for several blocks after the error" xmpDM:startTime="1913933" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Stream Modes of Operation Use block cipher as some form of pseudo-random number generator The random number bits are then" xmpDM:startTime="1914300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="XOR’ed with the message (as in stream cipher) Convert block cipher into stream cipher Cipher feedback (CFB) mode Output feedback" xmpDM:startTime="1914300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(OFB) mode Counter (CTR) mode" xmpDM:startTime="1914300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cipher Text Stealing (CTS) Alternative to padding which adds extra bytes." xmpDM:startTime="1914567" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Last 2 blocks are specially coded Tail bits of (n-1)st encoded block are added to nth block and order of" xmpDM:startTime="1914567" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="transmission of the two blocks is interchanged." xmpDM:startTime="1914567" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Þ Size of ciphertext is same as plane text." xmpDM:startTime="1914567" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="No extra bytes." xmpDM:startTime="1914567" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="" xmpDM:startTime="1914567" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Message Padding Last block may be shorter than others Þ Pad Pad with count of pad size [ANSI X.923]" xmpDM:startTime="1914900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="E.g.," xmpDM:startTime="1914900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="[ b1 b2 b3 0 0 0 0 5] = 3 data, 5 pad w 1 count byte A 1" xmpDM:startTime="1914900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="bit followed by 0 bits [ISO/IEC 9797-1] Any known byte value followed by zeros, e.g.," xmpDM:startTime="1914900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="80-00… Random data followed by count [ISO 10126] E.g.," xmpDM:startTime="1914900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="[b1 b2 b3 84 67 87 56 05] Each byte indicates the number of padded bytes [PKCS] E.g.," xmpDM:startTime="1914900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="[b1 b2 b3 05 05 05 05 05] Self-Describing Padding [RFC1570] Each pad octet contains its index starting with 1" xmpDM:startTime="1914900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="E.g.," xmpDM:startTime="1914900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="[b1 b2 b3 1 2 3 4 5] Ref: http://en.wikipedia.org/wiki/Padding_%28cryptography%29" xmpDM:startTime="1914900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="" xmpDM:startTime="1914900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of CBC Any change to a block affects all following ciphertext blocks Need Initialization Vector (IV) Must" xmpDM:startTime="1915300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="be known to sender &amp; receiver If sent in clear, attacker can change bits of first block, and change IV" xmpDM:startTime="1915300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="to compensate Hence IV must either be a fixed value, e.g.," xmpDM:startTime="1915300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="in Electronic Funds Transfers at Point of Sale (EFTPOS) Or must be sent encrypted in ECB mode before rest of" xmpDM:startTime="1915300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="message Sequential implementation." xmpDM:startTime="1915300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cannot be parallelized." xmpDM:startTime="1915300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="" xmpDM:startTime="1915300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cipher Block Chaining (CBC) Add random numbers before encrypting Previous cipher blocks is chained with current plaintext block Use an" xmpDM:startTime="1915667" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Initial Vector (IV) to start process Ci = EK(Pi XOR Ci-1) C-1 = IV" xmpDM:startTime="1915667" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of CBC Any change to a block affects all following ciphertext blocks Need Initialization Vector (IV) Must" xmpDM:startTime="1924767" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="be known to sender &amp; receiver If sent in clear, attacker can change bits of first block, and change IV" xmpDM:startTime="1924767" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="to compensate Hence IV must either be a fixed value, e.g.," xmpDM:startTime="1924767" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="in Electronic Funds Transfers at Point of Sale (EFTPOS) Or must be sent encrypted in ECB mode before rest of" xmpDM:startTime="1924767" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="message Sequential implementation." xmpDM:startTime="1924767" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cannot be parallelized." xmpDM:startTime="1924767" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="" xmpDM:startTime="1924767" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Message Padding Last block may be shorter than others Þ Pad Pad with count of pad size [ANSI X.923]" xmpDM:startTime="1925200" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="E.g.," xmpDM:startTime="1925200" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="[ b1 b2 b3 0 0 0 0 5] = 3 data, 5 pad w 1 count byte A 1" xmpDM:startTime="1925200" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="bit followed by 0 bits [ISO/IEC 9797-1] Any known byte value followed by zeros, e.g.," xmpDM:startTime="1925200" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="80-00… Random data followed by count [ISO 10126] E.g.," xmpDM:startTime="1925200" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="[b1 b2 b3 84 67 87 56 05] Each byte indicates the number of padded bytes [PKCS] E.g.," xmpDM:startTime="1925200" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="[b1 b2 b3 05 05 05 05 05] Self-Describing Padding [RFC1570] Each pad octet contains its index starting with 1" xmpDM:startTime="1925200" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="E.g.," xmpDM:startTime="1925200" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="[b1 b2 b3 1 2 3 4 5] Ref: http://en.wikipedia.org/wiki/Padding_%28cryptography%29" xmpDM:startTime="1925200" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="" xmpDM:startTime="1925200" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cipher Text Stealing (CTS) Alternative to padding which adds extra bytes." xmpDM:startTime="1925567" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Last 2 blocks are specially coded Tail bits of (n-1)st encoded block are added to nth block and order of" xmpDM:startTime="1925567" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="transmission of the two blocks is interchanged." xmpDM:startTime="1925567" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Þ Size of ciphertext is same as plane text." xmpDM:startTime="1925567" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="No extra bytes." xmpDM:startTime="1925567" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="" xmpDM:startTime="1925567" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Stream Modes of Operation Use block cipher as some form of pseudo-random number generator The random number bits are then" xmpDM:startTime="1926300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="XOR’ed with the message (as in stream cipher) Convert block cipher into stream cipher Cipher feedback (CFB) mode Output feedback" xmpDM:startTime="1926300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(OFB) mode Counter (CTR) mode" xmpDM:startTime="1926300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cipher Feedback (CFB) Message is added to the output of the block cipher Result is feed back for next stage" xmpDM:startTime="1926700" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(hence name) Standard allows any number of bit (1, 8, 64 or 128 etc) to be feed back, denoted CFB-1," xmpDM:startTime="1926700" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="CFB-8, CFB-64, CFB-128 etc Most efficient to use all bits in block (64 or 128) Ci = Pi XOR EK(Ci-1)" xmpDM:startTime="1926700" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="C-1 = IV Errors propagate for several blocks after the error" xmpDM:startTime="1926700" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Output Feedback (OFB) Output of the cipher is feed back (hence name) Feedback is independent of message Can be computed" xmpDM:startTime="1927167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="in advance Oi = EK(Oi-1) Ci = Pi XOR Oi O-1 = IV" xmpDM:startTime="1927167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of OFB Needs an IV which is unique for each use if ever reuse attacker can recover" xmpDM:startTime="2113533" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="outputs Bit errors do not propagate More vulnerable to message stream modification Sender &amp; receiver must remain in sync Only" xmpDM:startTime="2113533" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="use with full block feedback Subsequent research has shown that only full block feedback (i.e.," xmpDM:startTime="2113533" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="CFB-64 or CFB-128) should ever be used" xmpDM:startTime="2113533" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Output Feedback (OFB) Output of the cipher is feed back (hence name) Feedback is independent of message Can be computed" xmpDM:startTime="2130300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="in advance Oi = EK(Oi-1) Ci = Pi XOR Oi O-1 = IV" xmpDM:startTime="2130300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cipher Feedback (CFB) Message is added to the output of the block cipher Result is feed back for next stage" xmpDM:startTime="2155033" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(hence name) Standard allows any number of bit (1, 8, 64 or 128 etc) to be feed back, denoted CFB-1," xmpDM:startTime="2155033" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="CFB-8, CFB-64, CFB-128 etc Most efficient to use all bits in block (64 or 128) Ci = Pi XOR EK(Ci-1)" xmpDM:startTime="2155033" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="C-1 = IV Errors propagate for several blocks after the error" xmpDM:startTime="2155033" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Output Feedback (OFB) Output of the cipher is feed back (hence name) Feedback is independent of message Can be computed" xmpDM:startTime="2174967" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="in advance Oi = EK(Oi-1) Ci = Pi XOR Oi O-1 = IV" xmpDM:startTime="2174967" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of OFB Needs an IV which is unique for each use if ever reuse attacker can recover" xmpDM:startTime="2223300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="outputs Bit errors do not propagate More vulnerable to message stream modification Sender &amp; receiver must remain in sync Only" xmpDM:startTime="2223300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="use with full block feedback Subsequent research has shown that only full block feedback (i.e.," xmpDM:startTime="2223300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="CFB-64 or CFB-128) should ever be used" xmpDM:startTime="2223300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Output Feedback (OFB) Output of the cipher is feed back (hence name) Feedback is independent of message Can be computed" xmpDM:startTime="2298100" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="in advance Oi = EK(Oi-1) Ci = Pi XOR Oi O-1 = IV" xmpDM:startTime="2298100" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cipher Feedback (CFB) Message is added to the output of the block cipher Result is feed back for next stage" xmpDM:startTime="2315167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(hence name) Standard allows any number of bit (1, 8, 64 or 128 etc) to be feed back, denoted CFB-1," xmpDM:startTime="2315167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="CFB-8, CFB-64, CFB-128 etc Most efficient to use all bits in block (64 or 128) Ci = Pi XOR EK(Ci-1)" xmpDM:startTime="2315167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="C-1 = IV Errors propagate for several blocks after the error" xmpDM:startTime="2315167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Stream Modes of Operation Use block cipher as some form of pseudo-random number generator The random number bits are then" xmpDM:startTime="2315567" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="XOR’ed with the message (as in stream cipher) Convert block cipher into stream cipher Cipher feedback (CFB) mode Output feedback" xmpDM:startTime="2315567" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(OFB) mode Counter (CTR) mode" xmpDM:startTime="2315567" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cipher Feedback (CFB) Message is added to the output of the block cipher Result is feed back for next stage" xmpDM:startTime="2316367" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(hence name) Standard allows any number of bit (1, 8, 64 or 128 etc) to be feed back, denoted CFB-1," xmpDM:startTime="2316367" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="CFB-8, CFB-64, CFB-128 etc Most efficient to use all bits in block (64 or 128) Ci = Pi XOR EK(Ci-1)" xmpDM:startTime="2316367" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="C-1 = IV Errors propagate for several blocks after the error" xmpDM:startTime="2316367" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Output Feedback (OFB) Output of the cipher is feed back (hence name) Feedback is independent of message Can be computed" xmpDM:startTime="2319000" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="in advance Oi = EK(Oi-1) Ci = Pi XOR Oi O-1 = IV" xmpDM:startTime="2319000" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of OFB Needs an IV which is unique for each use if ever reuse attacker can recover" xmpDM:startTime="2319400" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="outputs Bit errors do not propagate More vulnerable to message stream modification Sender &amp; receiver must remain in sync Only" xmpDM:startTime="2319400" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="use with full block feedback Subsequent research has shown that only full block feedback (i.e.," xmpDM:startTime="2319400" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="CFB-64 or CFB-128) should ever be used" xmpDM:startTime="2319400" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Counter (CTR) Encrypt counter value rather than any feedback value Different key &amp; counter value for every plaintext block (never" xmpDM:startTime="2320667" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="reused) Oi = EK(i) Ci = Pi XOR Oi" xmpDM:startTime="2320667" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of OFB Needs an IV which is unique for each use if ever reuse attacker can recover" xmpDM:startTime="2326433" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="outputs Bit errors do not propagate More vulnerable to message stream modification Sender &amp; receiver must remain in sync Only" xmpDM:startTime="2326433" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="use with full block feedback Subsequent research has shown that only full block feedback (i.e.," xmpDM:startTime="2326433" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="CFB-64 or CFB-128) should ever be used" xmpDM:startTime="2326433" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Output Feedback (OFB) Output of the cipher is feed back (hence name) Feedback is independent of message Can be computed" xmpDM:startTime="2335600" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="in advance Oi = EK(Oi-1) Ci = Pi XOR Oi O-1 = IV" xmpDM:startTime="2335600" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of OFB Needs an IV which is unique for each use if ever reuse attacker can recover" xmpDM:startTime="2377000" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="outputs Bit errors do not propagate More vulnerable to message stream modification Sender &amp; receiver must remain in sync Only" xmpDM:startTime="2377000" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="use with full block feedback Subsequent research has shown that only full block feedback (i.e.," xmpDM:startTime="2377000" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="CFB-64 or CFB-128) should ever be used" xmpDM:startTime="2377000" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Counter (CTR) Encrypt counter value rather than any feedback value Different key &amp; counter value for every plaintext block (never" xmpDM:startTime="2379000" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="reused) Oi = EK(i) Ci = Pi XOR Oi" xmpDM:startTime="2379000" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of OFB Needs an IV which is unique for each use if ever reuse attacker can recover" xmpDM:startTime="2381233" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="outputs Bit errors do not propagate More vulnerable to message stream modification Sender &amp; receiver must remain in sync Only" xmpDM:startTime="2381233" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="use with full block feedback Subsequent research has shown that only full block feedback (i.e.," xmpDM:startTime="2381233" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="CFB-64 or CFB-128) should ever be used" xmpDM:startTime="2381233" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Counter (CTR) Encrypt counter value rather than any feedback value Different key &amp; counter value for every plaintext block (never" xmpDM:startTime="2438700" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="reused) Oi = EK(i) Ci = Pi XOR Oi" xmpDM:startTime="2438700" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of OFB Needs an IV which is unique for each use if ever reuse attacker can recover" xmpDM:startTime="2496033" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="outputs Bit errors do not propagate More vulnerable to message stream modification Sender &amp; receiver must remain in sync Only" xmpDM:startTime="2496033" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="use with full block feedback Subsequent research has shown that only full block feedback (i.e.," xmpDM:startTime="2496033" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="CFB-64 or CFB-128) should ever be used" xmpDM:startTime="2496033" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Counter (CTR) Encrypt counter value rather than any feedback value Different key &amp; counter value for every plaintext block (never" xmpDM:startTime="2515733" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="reused) Oi = EK(i) Ci = Pi XOR Oi" xmpDM:startTime="2515733" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of CTR Efficiency Can do parallel encryptions in h/w or s/w Can preprocess in advance of need" xmpDM:startTime="2685100" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Good for bursty high speed links Random access to encrypted data blocks Provable security (good as other modes) But must" xmpDM:startTime="2685100" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="never reuse key/counter values, otherwise could break" xmpDM:startTime="2685100" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Counter (CTR) Encrypt counter value rather than any feedback value Different key &amp; counter value for every plaintext block (never" xmpDM:startTime="2724800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="reused) Oi = EK(i) Ci = Pi XOR Oi" xmpDM:startTime="2724800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of CTR Efficiency Can do parallel encryptions in h/w or s/w Can preprocess in advance of need" xmpDM:startTime="2753600" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Good for bursty high speed links Random access to encrypted data blocks Provable security (good as other modes) But must" xmpDM:startTime="2753600" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="never reuse key/counter values, otherwise could break" xmpDM:startTime="2753600" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Storage Encryption File encryption: Different keys for different files May not protect metadata, e.g.," xmpDM:startTime="2776600" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="filename, creation date, Individual files can be backed up Encrypting File System (EFS) in NTFS provides this svc Disk encryption:" xmpDM:startTime="2776600" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Single key for whole disk or separate keys for each partition Master boot record (MBR) may or may not be" xmpDM:startTime="2776600" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="encrypted Boot partition may or may not be encrypted." xmpDM:startTime="2776600" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Operating system stores the key in the memory Can be read by an attacker by cold boot Trusted Platform Module" xmpDM:startTime="2776600" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(TPM): A secure coprocessor chip on the motherboard that can authenticate a device Þ Disk can be read only on" xmpDM:startTime="2776600" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="that system." xmpDM:startTime="2776600" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Recovery is possible with a decryption password or token" xmpDM:startTime="2776600" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Storage Encryption (Cont) If IV is predictable, CBC is not usable in storage because the plain text is chosen by" xmpDM:startTime="2778167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="the writer Ciphertext is easily available to other users of the same disk Two messages with the first blocks=bIV1 and" xmpDM:startTime="2778167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="b  IV2 will both encrypt to the same ciphertext Need to be able to read/write blocks without reading/writing other" xmpDM:startTime="2778167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="blocks CBC" xmpDM:startTime="2778167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Storage Encryption File encryption: Different keys for different files May not protect metadata, e.g.," xmpDM:startTime="2780867" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="filename, creation date, Individual files can be backed up Encrypting File System (EFS) in NTFS provides this svc Disk encryption:" xmpDM:startTime="2780867" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Single key for whole disk or separate keys for each partition Master boot record (MBR) may or may not be" xmpDM:startTime="2780867" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="encrypted Boot partition may or may not be encrypted." xmpDM:startTime="2780867" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Operating system stores the key in the memory Can be read by an attacker by cold boot Trusted Platform Module" xmpDM:startTime="2780867" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(TPM): A secure coprocessor chip on the motherboard that can authenticate a device Þ Disk can be read only on" xmpDM:startTime="2780867" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="that system." xmpDM:startTime="2780867" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Recovery is possible with a decryption password or token" xmpDM:startTime="2780867" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of CTR Efficiency Can do parallel encryptions in h/w or s/w Can preprocess in advance of need" xmpDM:startTime="2781600" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Good for bursty high speed links Random access to encrypted data blocks Provable security (good as other modes) But must" xmpDM:startTime="2781600" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="never reuse key/counter values, otherwise could break" xmpDM:startTime="2781600" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Counter (CTR) Encrypt counter value rather than any feedback value Different key &amp; counter value for every plaintext block (never" xmpDM:startTime="2877367" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="reused) Oi = EK(i) Ci = Pi XOR Oi" xmpDM:startTime="2877367" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of CTR Efficiency Can do parallel encryptions in h/w or s/w Can preprocess in advance of need" xmpDM:startTime="2895933" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Good for bursty high speed links Random access to encrypted data blocks Provable security (good as other modes) But must" xmpDM:startTime="2895933" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="never reuse key/counter values, otherwise could break" xmpDM:startTime="2895933" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Storage Encryption File encryption: Different keys for different files May not protect metadata, e.g.," xmpDM:startTime="2898800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="filename, creation date, Individual files can be backed up Encrypting File System (EFS) in NTFS provides this svc Disk encryption:" xmpDM:startTime="2898800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Single key for whole disk or separate keys for each partition Master boot record (MBR) may or may not be" xmpDM:startTime="2898800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="encrypted Boot partition may or may not be encrypted." xmpDM:startTime="2898800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Operating system stores the key in the memory Can be read by an attacker by cold boot Trusted Platform Module" xmpDM:startTime="2898800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(TPM): A secure coprocessor chip on the motherboard that can authenticate a device Þ Disk can be read only on" xmpDM:startTime="2898800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="that system." xmpDM:startTime="2898800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Recovery is possible with a decryption password or token" xmpDM:startTime="2898800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Storage Encryption (Cont) If IV is predictable, CBC is not usable in storage because the plain text is chosen by" xmpDM:startTime="3623800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="the writer Ciphertext is easily available to other users of the same disk Two messages with the first blocks=bIV1 and" xmpDM:startTime="3623800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="b  IV2 will both encrypt to the same ciphertext Need to be able to read/write blocks without reading/writing other" xmpDM:startTime="3623800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="blocks CBC" xmpDM:startTime="3623800" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Storage Encryption File encryption: Different keys for different files May not protect metadata, e.g.," xmpDM:startTime="3717233" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="filename, creation date, Individual files can be backed up Encrypting File System (EFS) in NTFS provides this svc Disk encryption:" xmpDM:startTime="3717233" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Single key for whole disk or separate keys for each partition Master boot record (MBR) may or may not be" xmpDM:startTime="3717233" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="encrypted Boot partition may or may not be encrypted." xmpDM:startTime="3717233" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Operating system stores the key in the memory Can be read by an attacker by cold boot Trusted Platform Module" xmpDM:startTime="3717233" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(TPM): A secure coprocessor chip on the motherboard that can authenticate a device Þ Disk can be read only on" xmpDM:startTime="3717233" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="that system." xmpDM:startTime="3717233" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Recovery is possible with a decryption password or token" xmpDM:startTime="3717233" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of CTR Efficiency Can do parallel encryptions in h/w or s/w Can preprocess in advance of need" xmpDM:startTime="3717600" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Good for bursty high speed links Random access to encrypted data blocks Provable security (good as other modes) But must" xmpDM:startTime="3717600" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="never reuse key/counter values, otherwise could break" xmpDM:startTime="3717600" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Counter (CTR) Encrypt counter value rather than any feedback value Different key &amp; counter value for every plaintext block (never" xmpDM:startTime="3717833" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="reused) Oi = EK(i) Ci = Pi XOR Oi" xmpDM:startTime="3717833" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of OFB Needs an IV which is unique for each use if ever reuse attacker can recover" xmpDM:startTime="3718167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="outputs Bit errors do not propagate More vulnerable to message stream modification Sender &amp; receiver must remain in sync Only" xmpDM:startTime="3718167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="use with full block feedback Subsequent research has shown that only full block feedback (i.e.," xmpDM:startTime="3718167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="CFB-64 or CFB-128) should ever be used" xmpDM:startTime="3718167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Output Feedback (OFB) Output of the cipher is feed back (hence name) Feedback is independent of message Can be computed" xmpDM:startTime="3718600" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="in advance Oi = EK(Oi-1) Ci = Pi XOR Oi O-1 = IV" xmpDM:startTime="3718600" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cipher Feedback (CFB) Message is added to the output of the block cipher Result is feed back for next stage" xmpDM:startTime="3719267" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(hence name) Standard allows any number of bit (1, 8, 64 or 128 etc) to be feed back, denoted CFB-1," xmpDM:startTime="3719267" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="CFB-8, CFB-64, CFB-128 etc Most efficient to use all bits in block (64 or 128) Ci = Pi XOR EK(Ci-1)" xmpDM:startTime="3719267" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="C-1 = IV Errors propagate for several blocks after the error" xmpDM:startTime="3719267" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Output Feedback (OFB) Output of the cipher is feed back (hence name) Feedback is independent of message Can be computed" xmpDM:startTime="3720833" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="in advance Oi = EK(Oi-1) Ci = Pi XOR Oi O-1 = IV" xmpDM:startTime="3720833" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of OFB Needs an IV which is unique for each use if ever reuse attacker can recover" xmpDM:startTime="3721300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="outputs Bit errors do not propagate More vulnerable to message stream modification Sender &amp; receiver must remain in sync Only" xmpDM:startTime="3721300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="use with full block feedback Subsequent research has shown that only full block feedback (i.e.," xmpDM:startTime="3721300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="CFB-64 or CFB-128) should ever be used" xmpDM:startTime="3721300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Counter (CTR) Encrypt counter value rather than any feedback value Different key &amp; counter value for every plaintext block (never" xmpDM:startTime="3721700" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="reused) Oi = EK(i) Ci = Pi XOR Oi" xmpDM:startTime="3721700" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of CTR Efficiency Can do parallel encryptions in h/w or s/w Can preprocess in advance of need" xmpDM:startTime="3722300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Good for bursty high speed links Random access to encrypted data blocks Provable security (good as other modes) But must" xmpDM:startTime="3722300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="never reuse key/counter values, otherwise could break" xmpDM:startTime="3722300" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Storage Encryption File encryption: Different keys for different files May not protect metadata, e.g.," xmpDM:startTime="3722767" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="filename, creation date, Individual files can be backed up Encrypting File System (EFS) in NTFS provides this svc Disk encryption:" xmpDM:startTime="3722767" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Single key for whole disk or separate keys for each partition Master boot record (MBR) may or may not be" xmpDM:startTime="3722767" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="encrypted Boot partition may or may not be encrypted." xmpDM:startTime="3722767" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Operating system stores the key in the memory Can be read by an attacker by cold boot Trusted Platform Module" xmpDM:startTime="3722767" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(TPM): A secure coprocessor chip on the motherboard that can authenticate a device Þ Disk can be read only on" xmpDM:startTime="3722767" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="that system." xmpDM:startTime="3722767" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Recovery is possible with a decryption password or token" xmpDM:startTime="3722767" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Storage Encryption (Cont) If IV is predictable, CBC is not usable in storage because the plain text is chosen by" xmpDM:startTime="3723233" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="the writer Ciphertext is easily available to other users of the same disk Two messages with the first blocks=bIV1 and" xmpDM:startTime="3723233" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="b  IV2 will both encrypt to the same ciphertext Need to be able to read/write blocks without reading/writing other" xmpDM:startTime="3723233" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="blocks CBC" xmpDM:startTime="3723233" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Storage Encryption File encryption: Different keys for different files May not protect metadata, e.g.," xmpDM:startTime="3753833" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="filename, creation date, Individual files can be backed up Encrypting File System (EFS) in NTFS provides this svc Disk encryption:" xmpDM:startTime="3753833" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Single key for whole disk or separate keys for each partition Master boot record (MBR) may or may not be" xmpDM:startTime="3753833" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="encrypted Boot partition may or may not be encrypted." xmpDM:startTime="3753833" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Operating system stores the key in the memory Can be read by an attacker by cold boot Trusted Platform Module" xmpDM:startTime="3753833" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(TPM): A secure coprocessor chip on the motherboard that can authenticate a device Þ Disk can be read only on" xmpDM:startTime="3753833" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="that system." xmpDM:startTime="3753833" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Recovery is possible with a decryption password or token" xmpDM:startTime="3753833" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of CTR Efficiency Can do parallel encryptions in h/w or s/w Can preprocess in advance of need" xmpDM:startTime="3754233" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Good for bursty high speed links Random access to encrypted data blocks Provable security (good as other modes) But must" xmpDM:startTime="3754233" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="never reuse key/counter values, otherwise could break" xmpDM:startTime="3754233" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Counter (CTR) Encrypt counter value rather than any feedback value Different key &amp; counter value for every plaintext block (never" xmpDM:startTime="3754700" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="reused) Oi = EK(i) Ci = Pi XOR Oi" xmpDM:startTime="3754700" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of CTR Efficiency Can do parallel encryptions in h/w or s/w Can preprocess in advance of need" xmpDM:startTime="3763433" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Good for bursty high speed links Random access to encrypted data blocks Provable security (good as other modes) But must" xmpDM:startTime="3763433" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="never reuse key/counter values, otherwise could break" xmpDM:startTime="3763433" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Storage Encryption File encryption: Different keys for different files May not protect metadata, e.g.," xmpDM:startTime="3763900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="filename, creation date, Individual files can be backed up Encrypting File System (EFS) in NTFS provides this svc Disk encryption:" xmpDM:startTime="3763900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Single key for whole disk or separate keys for each partition Master boot record (MBR) may or may not be" xmpDM:startTime="3763900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="encrypted Boot partition may or may not be encrypted." xmpDM:startTime="3763900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Operating system stores the key in the memory Can be read by an attacker by cold boot Trusted Platform Module" xmpDM:startTime="3763900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(TPM): A secure coprocessor chip on the motherboard that can authenticate a device Þ Disk can be read only on" xmpDM:startTime="3763900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="that system." xmpDM:startTime="3763900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Recovery is possible with a decryption password or token" xmpDM:startTime="3763900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Storage Encryption (Cont) If IV is predictable, CBC is not usable in storage because the plain text is chosen by" xmpDM:startTime="3764400" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="the writer Ciphertext is easily available to other users of the same disk Two messages with the first blocks=bIV1 and" xmpDM:startTime="3764400" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="b  IV2 will both encrypt to the same ciphertext Need to be able to read/write blocks without reading/writing other" xmpDM:startTime="3764400" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="blocks CBC" xmpDM:startTime="3764400" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="XTS-AES Mode XTS = XEX-based Tweaked Codebook mode with Ciphertext Stealing (XEX = Xor-Encrypt-xor) Creates a unique IV for each" xmpDM:startTime="3788567" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="block using AES and 2 keys Tj = EK2(i)αj Size of K2 = size of block Cj = EK1(PjTj)Tj K1" xmpDM:startTime="3788567" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="256 bit for AES-256 where i is logical sector # &amp; j is block # (sector = n blocks) a" xmpDM:startTime="3788567" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="= primitive element in GF(2128) defined by polynomial x" xmpDM:startTime="3788567" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of XTS-AES Multiplication is modulo x128+x7+x2+x+1 in GF(2128) Efficiency Can do parallel encryptions in h/w or s/w" xmpDM:startTime="4105333" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Random access to encrypted data blocks Has both nonce &amp; counter Defined in IEEE Std 1619-2007 for block oriented storage" xmpDM:startTime="4105333" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="use Implemented in numerous packages and operating systems including TrueCrypt, FreeBSD, and OpenBSD softraid disk encryption software (also native in" xmpDM:startTime="4105333" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Mac OSX Lion’s FileVault), in hardware-based media encryption devices by the SPYRUS Hydra PC Digital Attaché and the Kingston DataTraveler" xmpDM:startTime="4105333" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="5000." xmpDM:startTime="4105333" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Ref: http://en.wikipedia.org/wiki/Disk_encryption_theory" xmpDM:startTime="4105333" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="" xmpDM:startTime="4105333" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="XTS-AES Mode XTS = XEX-based Tweaked Codebook mode with Ciphertext Stealing (XEX = Xor-Encrypt-xor) Creates a unique IV for each" xmpDM:startTime="4106833" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="block using AES and 2 keys Tj = EK2(i)αj Size of K2 = size of block Cj = EK1(PjTj)Tj K1" xmpDM:startTime="4106833" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="256 bit for AES-256 where i is logical sector # &amp; j is block # (sector = n blocks) a" xmpDM:startTime="4106833" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="= primitive element in GF(2128) defined by polynomial x" xmpDM:startTime="4106833" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Storage Encryption (Cont) If IV is predictable, CBC is not usable in storage because the plain text is chosen by" xmpDM:startTime="4126000" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="the writer Ciphertext is easily available to other users of the same disk Two messages with the first blocks=bIV1 and" xmpDM:startTime="4126000" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="b  IV2 will both encrypt to the same ciphertext Need to be able to read/write blocks without reading/writing other" xmpDM:startTime="4126000" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="blocks CBC" xmpDM:startTime="4126000" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Storage Encryption File encryption: Different keys for different files May not protect metadata, e.g.," xmpDM:startTime="4126333" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="filename, creation date, Individual files can be backed up Encrypting File System (EFS) in NTFS provides this svc Disk encryption:" xmpDM:startTime="4126333" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Single key for whole disk or separate keys for each partition Master boot record (MBR) may or may not be" xmpDM:startTime="4126333" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="encrypted Boot partition may or may not be encrypted." xmpDM:startTime="4126333" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Operating system stores the key in the memory Can be read by an attacker by cold boot Trusted Platform Module" xmpDM:startTime="4126333" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(TPM): A secure coprocessor chip on the motherboard that can authenticate a device Þ Disk can be read only on" xmpDM:startTime="4126333" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="that system." xmpDM:startTime="4126333" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Recovery is possible with a decryption password or token" xmpDM:startTime="4126333" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of CTR Efficiency Can do parallel encryptions in h/w or s/w Can preprocess in advance of need" xmpDM:startTime="4126667" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Good for bursty high speed links Random access to encrypted data blocks Provable security (good as other modes) But must" xmpDM:startTime="4126667" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="never reuse key/counter values, otherwise could break" xmpDM:startTime="4126667" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Counter (CTR) Encrypt counter value rather than any feedback value Different key &amp; counter value for every plaintext block (never" xmpDM:startTime="4127167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="reused) Oi = EK(i) Ci = Pi XOR Oi" xmpDM:startTime="4127167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of OFB Needs an IV which is unique for each use if ever reuse attacker can recover" xmpDM:startTime="4128133" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="outputs Bit errors do not propagate More vulnerable to message stream modification Sender &amp; receiver must remain in sync Only" xmpDM:startTime="4128133" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="use with full block feedback Subsequent research has shown that only full block feedback (i.e.," xmpDM:startTime="4128133" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="CFB-64 or CFB-128) should ever be used" xmpDM:startTime="4128133" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Output Feedback (OFB) Output of the cipher is feed back (hence name) Feedback is independent of message Can be computed" xmpDM:startTime="4128667" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="in advance Oi = EK(Oi-1) Ci = Pi XOR Oi O-1 = IV" xmpDM:startTime="4128667" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cipher Feedback (CFB) Message is added to the output of the block cipher Result is feed back for next stage" xmpDM:startTime="4129200" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(hence name) Standard allows any number of bit (1, 8, 64 or 128 etc) to be feed back, denoted CFB-1," xmpDM:startTime="4129200" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="CFB-8, CFB-64, CFB-128 etc Most efficient to use all bits in block (64 or 128) Ci = Pi XOR EK(Ci-1)" xmpDM:startTime="4129200" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="C-1 = IV Errors propagate for several blocks after the error" xmpDM:startTime="4129200" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Stream Modes of Operation Use block cipher as some form of pseudo-random number generator The random number bits are then" xmpDM:startTime="4130033" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="XOR’ed with the message (as in stream cipher) Convert block cipher into stream cipher Cipher feedback (CFB) mode Output feedback" xmpDM:startTime="4130033" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(OFB) mode Counter (CTR) mode" xmpDM:startTime="4130033" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cipher Text Stealing (CTS) Alternative to padding which adds extra bytes." xmpDM:startTime="4130467" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Last 2 blocks are specially coded Tail bits of (n-1)st encoded block are added to nth block and order of" xmpDM:startTime="4130467" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="transmission of the two blocks is interchanged." xmpDM:startTime="4130467" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Þ Size of ciphertext is same as plane text." xmpDM:startTime="4130467" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="No extra bytes." xmpDM:startTime="4130467" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="" xmpDM:startTime="4130467" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Stream Modes of Operation Use block cipher as some form of pseudo-random number generator The random number bits are then" xmpDM:startTime="4134533" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="XOR’ed with the message (as in stream cipher) Convert block cipher into stream cipher Cipher feedback (CFB) mode Output feedback" xmpDM:startTime="4134533" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(OFB) mode Counter (CTR) mode" xmpDM:startTime="4134533" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Cipher Feedback (CFB) Message is added to the output of the block cipher Result is feed back for next stage" xmpDM:startTime="4134900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(hence name) Standard allows any number of bit (1, 8, 64 or 128 etc) to be feed back, denoted CFB-1," xmpDM:startTime="4134900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="CFB-8, CFB-64, CFB-128 etc Most efficient to use all bits in block (64 or 128) Ci = Pi XOR EK(Ci-1)" xmpDM:startTime="4134900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="C-1 = IV Errors propagate for several blocks after the error" xmpDM:startTime="4134900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Output Feedback (OFB) Output of the cipher is feed back (hence name) Feedback is independent of message Can be computed" xmpDM:startTime="4135233" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="in advance Oi = EK(Oi-1) Ci = Pi XOR Oi O-1 = IV" xmpDM:startTime="4135233" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of OFB Needs an IV which is unique for each use if ever reuse attacker can recover" xmpDM:startTime="4135567" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="outputs Bit errors do not propagate More vulnerable to message stream modification Sender &amp; receiver must remain in sync Only" xmpDM:startTime="4135567" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="use with full block feedback Subsequent research has shown that only full block feedback (i.e.," xmpDM:startTime="4135567" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="CFB-64 or CFB-128) should ever be used" xmpDM:startTime="4135567" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Counter (CTR) Encrypt counter value rather than any feedback value Different key &amp; counter value for every plaintext block (never" xmpDM:startTime="4135933" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="reused) Oi = EK(i) Ci = Pi XOR Oi" xmpDM:startTime="4135933" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of CTR Efficiency Can do parallel encryptions in h/w or s/w Can preprocess in advance of need" xmpDM:startTime="4136500" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Good for bursty high speed links Random access to encrypted data blocks Provable security (good as other modes) But must" xmpDM:startTime="4136500" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="never reuse key/counter values, otherwise could break" xmpDM:startTime="4136500" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Storage Encryption File encryption: Different keys for different files May not protect metadata, e.g.," xmpDM:startTime="4136867" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="filename, creation date, Individual files can be backed up Encrypting File System (EFS) in NTFS provides this svc Disk encryption:" xmpDM:startTime="4136867" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Single key for whole disk or separate keys for each partition Master boot record (MBR) may or may not be" xmpDM:startTime="4136867" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="encrypted Boot partition may or may not be encrypted." xmpDM:startTime="4136867" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Operating system stores the key in the memory Can be read by an attacker by cold boot Trusted Platform Module" xmpDM:startTime="4136867" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="(TPM): A secure coprocessor chip on the motherboard that can authenticate a device Þ Disk can be read only on" xmpDM:startTime="4136867" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="that system." xmpDM:startTime="4136867" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Recovery is possible with a decryption password or token" xmpDM:startTime="4136867" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Storage Encryption (Cont) If IV is predictable, CBC is not usable in storage because the plain text is chosen by" xmpDM:startTime="4137367" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="the writer Ciphertext is easily available to other users of the same disk Two messages with the first blocks=bIV1 and" xmpDM:startTime="4137367" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="b  IV2 will both encrypt to the same ciphertext Need to be able to read/write blocks without reading/writing other" xmpDM:startTime="4137367" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="blocks CBC" xmpDM:startTime="4137367" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="XTS-AES Mode XTS = XEX-based Tweaked Codebook mode with Ciphertext Stealing (XEX = Xor-Encrypt-xor) Creates a unique IV for each" xmpDM:startTime="4137733" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="block using AES and 2 keys Tj = EK2(i)αj Size of K2 = size of block Cj = EK1(PjTj)Tj K1" xmpDM:startTime="4137733" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="256 bit for AES-256 where i is logical sector # &amp; j is block # (sector = n blocks) a" xmpDM:startTime="4137733" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="= primitive element in GF(2128) defined by polynomial x" xmpDM:startTime="4137733" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of XTS-AES Multiplication is modulo x128+x7+x2+x+1 in GF(2128) Efficiency Can do parallel encryptions in h/w or s/w" xmpDM:startTime="4206633" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Random access to encrypted data blocks Has both nonce &amp; counter Defined in IEEE Std 1619-2007 for block oriented storage" xmpDM:startTime="4206633" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="use Implemented in numerous packages and operating systems including TrueCrypt, FreeBSD, and OpenBSD softraid disk encryption software (also native in" xmpDM:startTime="4206633" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Mac OSX Lion’s FileVault), in hardware-based media encryption devices by the SPYRUS Hydra PC Digital Attaché and the Kingston DataTraveler" xmpDM:startTime="4206633" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="5000." xmpDM:startTime="4206633" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Ref: http://en.wikipedia.org/wiki/Disk_encryption_theory" xmpDM:startTime="4206633" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="" xmpDM:startTime="4206633" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="XTS-AES Mode XTS = XEX-based Tweaked Codebook mode with Ciphertext Stealing (XEX = Xor-Encrypt-xor) Creates a unique IV for each" xmpDM:startTime="4298067" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="block using AES and 2 keys Tj = EK2(i)αj Size of K2 = size of block Cj = EK1(PjTj)Tj K1" xmpDM:startTime="4298067" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="256 bit for AES-256 where i is logical sector # &amp; j is block # (sector = n blocks) a" xmpDM:startTime="4298067" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="= primitive element in GF(2128) defined by polynomial x" xmpDM:startTime="4298067" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Advantages and Limitations of XTS-AES Multiplication is modulo x128+x7+x2+x+1 in GF(2128) Efficiency Can do parallel encryptions in h/w or s/w" xmpDM:startTime="4305433" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Random access to encrypted data blocks Has both nonce &amp; counter Defined in IEEE Std 1619-2007 for block oriented storage" xmpDM:startTime="4305433" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="use Implemented in numerous packages and operating systems including TrueCrypt, FreeBSD, and OpenBSD softraid disk encryption software (also native in" xmpDM:startTime="4305433" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Mac OSX Lion’s FileVault), in hardware-based media encryption devices by the SPYRUS Hydra PC Digital Attaché and the Kingston DataTraveler" xmpDM:startTime="4305433" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="5000." xmpDM:startTime="4305433" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Ref: http://en.wikipedia.org/wiki/Disk_encryption_theory" xmpDM:startTime="4305433" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="" xmpDM:startTime="4305433" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Summary 3DES generally uses E-D-E with 2 keys Þ112b protection ECB: Same ciphertext for the same plaintext Þ Easier to" xmpDM:startTime="4305900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="break (e) XTS-AES" xmpDM:startTime="4305900" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Homework 6 For each of the modes ECB, CBC and CTR: Identify whether decrypted plaintext block P3 will be corrupted" xmpDM:startTime="4308167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="if there is an error in block C1 of the transmitted cipher text." xmpDM:startTime="4308167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Assuming that the ciphertext contains N blocks, and that there was a bit error in the source version of P1," xmpDM:startTime="4308167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="identify through how many ciphertext blocks this error is propagated." xmpDM:startTime="4308167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="" xmpDM:startTime="4308167" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Summary 3DES generally uses E-D-E with 2 keys Þ112b protection ECB: Same ciphertext for the same plaintext Þ Easier to" xmpDM:startTime="4309267" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="break (e) XTS-AES" xmpDM:startTime="4309267" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Homework 6 For each of the modes ECB, CBC and CTR: Identify whether decrypted plaintext block P3 will be corrupted" xmpDM:startTime="4381433" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="if there is an error in block C1 of the transmitted cipher text." xmpDM:startTime="4381433" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="Assuming that the ciphertext contains N blocks, and that there was a bit error in the source version of P1," xmpDM:startTime="4381433" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="identify through how many ciphertext blocks this error is propagated." xmpDM:startTime="4381433" xmpDM:duration="1000"/></rdf:li><rdf:li><rdf:Description xmpDM:name="" xmpDM:startTime="4381433" xmpDM:duration="1000"/></rdf:li></rdf:Seq>
                     </xmpDM:markers>
                  </rdf:Description>
               </rdf:li>
               <rdf:li>
                  <rdf:Description xmpDM:trackType="TableOfContents" xmpDM:frameRate="f1000" xmpDM:trackName="Table of Contents">
                     <xmpDM:markers>
                        <rdf:Seq>
                           <rdf:li><rdf:Description xmpDM:name="   1. Electronic Codebook (ECB) Mode" xmpDM:startTime="0" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="0" tscDM:imageoffset="0" tscDM:imagerect="0, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="   2. ECB Limitations" xmpDM:startTime="23900" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="1" tscDM:imageoffset="0" tscDM:imagerect="75, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="   3. Cipher Block Chaining (CBC) " xmpDM:startTime="95533" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="2" tscDM:imageoffset="0" tscDM:imagerect="150, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="   4. ECB Limitations" xmpDM:startTime="196300" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="3" tscDM:imageoffset="0" tscDM:imagerect="225, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="   5. Cipher Block Chaining (CBC) " xmpDM:startTime="209567" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="4" tscDM:imageoffset="0" tscDM:imagerect="300, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="   6. Advantages and Limitations of CBC" xmpDM:startTime="222800" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="5" tscDM:imageoffset="0" tscDM:imagerect="375, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="   7. Cipher Block Chaining (CBC) " xmpDM:startTime="249700" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="6" tscDM:imageoffset="0" tscDM:imagerect="450, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="   8. Advantages and Limitations of CBC" xmpDM:startTime="294900" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="7" tscDM:imageoffset="0" tscDM:imagerect="525, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="   9. Cipher Block Chaining (CBC) " xmpDM:startTime="320567" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="8" tscDM:imageoffset="0" tscDM:imagerect="600, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  10. Advantages and Limitations of CBC" xmpDM:startTime="334667" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="9" tscDM:imageoffset="0" tscDM:imagerect="675, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  11. Message Padding" xmpDM:startTime="372167" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="10" tscDM:imageoffset="0" tscDM:imagerect="750, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  12. Cipher Text Stealing (CTS)" xmpDM:startTime="860767" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="11" tscDM:imageoffset="0" tscDM:imagerect="825, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  13. Stream Modes of Operation" xmpDM:startTime="1116000" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="12" tscDM:imageoffset="0" tscDM:imagerect="900, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  14. Cipher Feedback (CFB)" xmpDM:startTime="1269900" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="13" tscDM:imageoffset="0" tscDM:imagerect="975, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  15. Output Feedback (OFB)" xmpDM:startTime="1668067" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="14" tscDM:imageoffset="0" tscDM:imagerect="1050, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  16. Cipher Feedback (CFB)" xmpDM:startTime="1719400" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="15" tscDM:imageoffset="0" tscDM:imagerect="1125, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  17. Output Feedback (OFB)" xmpDM:startTime="1722233" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="16" tscDM:imageoffset="0" tscDM:imagerect="1200, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  18. Cipher Feedback (CFB)" xmpDM:startTime="1793833" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="17" tscDM:imageoffset="0" tscDM:imagerect="1275, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  19. Stream Modes of Operation" xmpDM:startTime="1811967" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="18" tscDM:imageoffset="0" tscDM:imagerect="1350, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  20. Cipher Text Stealing (CTS)" xmpDM:startTime="1812433" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="19" tscDM:imageoffset="0" tscDM:imagerect="1425, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  21. Message Padding" xmpDM:startTime="1812633" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="20" tscDM:imageoffset="0" tscDM:imagerect="1500, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  22. Advantages and Limitations of CBC" xmpDM:startTime="1812800" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="21" tscDM:imageoffset="0" tscDM:imagerect="1575, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  23. Cipher Block Chaining (CBC) " xmpDM:startTime="1813000" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="22" tscDM:imageoffset="0" tscDM:imagerect="1650, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  24. Advantages and Limitations of CBC" xmpDM:startTime="1858500" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="23" tscDM:imageoffset="0" tscDM:imagerect="1725, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  25. Message Padding" xmpDM:startTime="1859100" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="24" tscDM:imageoffset="0" tscDM:imagerect="1800, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  26. Cipher Text Stealing (CTS)" xmpDM:startTime="1859533" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="25" tscDM:imageoffset="0" tscDM:imagerect="1875, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  27. Stream Modes of Operation" xmpDM:startTime="1860000" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="26" tscDM:imageoffset="0" tscDM:imagerect="1950, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  28. Cipher Feedback (CFB)" xmpDM:startTime="1860600" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="27" tscDM:imageoffset="0" tscDM:imagerect="2025, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  29. Output Feedback (OFB)" xmpDM:startTime="1861300" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="28" tscDM:imageoffset="0" tscDM:imagerect="2100, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  30. Cipher Feedback (CFB)" xmpDM:startTime="1913933" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="29" tscDM:imageoffset="0" tscDM:imagerect="2175, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  31. Stream Modes of Operation" xmpDM:startTime="1914300" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="30" tscDM:imageoffset="0" tscDM:imagerect="2250, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  32. Cipher Text Stealing (CTS)" xmpDM:startTime="1914567" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="31" tscDM:imageoffset="0" tscDM:imagerect="2325, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  33. Message Padding" xmpDM:startTime="1914900" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="32" tscDM:imageoffset="0" tscDM:imagerect="2400, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  34. Advantages and Limitations of CBC" xmpDM:startTime="1915300" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="33" tscDM:imageoffset="0" tscDM:imagerect="2475, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  35. Cipher Block Chaining (CBC) " xmpDM:startTime="1915667" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="34" tscDM:imageoffset="0" tscDM:imagerect="2550, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  36. Advantages and Limitations of CBC" xmpDM:startTime="1924767" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="35" tscDM:imageoffset="0" tscDM:imagerect="2625, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  37. Message Padding" xmpDM:startTime="1925200" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="36" tscDM:imageoffset="0" tscDM:imagerect="2700, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  38. Cipher Text Stealing (CTS)" xmpDM:startTime="1925567" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="37" tscDM:imageoffset="0" tscDM:imagerect="2775, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  39. Stream Modes of Operation" xmpDM:startTime="1926300" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="38" tscDM:imageoffset="0" tscDM:imagerect="2850, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  40. Cipher Feedback (CFB)" xmpDM:startTime="1926700" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="39" tscDM:imageoffset="0" tscDM:imagerect="2925, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  41. Output Feedback (OFB)" xmpDM:startTime="1927167" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="40" tscDM:imageoffset="0" tscDM:imagerect="3000, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  42. Advantages and Limitations of OFB" xmpDM:startTime="2113533" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="41" tscDM:imageoffset="0" tscDM:imagerect="3075, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  43. Output Feedback (OFB)" xmpDM:startTime="2130300" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="42" tscDM:imageoffset="0" tscDM:imagerect="3150, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  44. Cipher Feedback (CFB)" xmpDM:startTime="2155033" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="43" tscDM:imageoffset="0" tscDM:imagerect="3225, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  45. Output Feedback (OFB)" xmpDM:startTime="2174967" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="44" tscDM:imageoffset="0" tscDM:imagerect="3300, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  46. Advantages and Limitations of OFB" xmpDM:startTime="2223300" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="45" tscDM:imageoffset="0" tscDM:imagerect="3375, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  47. Output Feedback (OFB)" xmpDM:startTime="2298100" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="46" tscDM:imageoffset="0" tscDM:imagerect="3450, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  48. Cipher Feedback (CFB)" xmpDM:startTime="2315167" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="47" tscDM:imageoffset="0" tscDM:imagerect="3525, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  49. Stream Modes of Operation" xmpDM:startTime="2315567" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="48" tscDM:imageoffset="0" tscDM:imagerect="3600, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  50. Cipher Feedback (CFB)" xmpDM:startTime="2316367" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="49" tscDM:imageoffset="0" tscDM:imagerect="3675, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  51. Output Feedback (OFB)" xmpDM:startTime="2319000" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="50" tscDM:imageoffset="0" tscDM:imagerect="3750, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  52. Advantages and Limitations of OFB" xmpDM:startTime="2319400" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="51" tscDM:imageoffset="0" tscDM:imagerect="3825, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  53. Counter (CTR)" xmpDM:startTime="2320667" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="52" tscDM:imageoffset="0" tscDM:imagerect="3900, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  54. Advantages and Limitations of OFB" xmpDM:startTime="2326433" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="53" tscDM:imageoffset="0" tscDM:imagerect="3975, 0, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  55. Output Feedback (OFB)" xmpDM:startTime="2335600" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="54" tscDM:imageoffset="0" tscDM:imagerect="50, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  56. Advantages and Limitations of OFB" xmpDM:startTime="2377000" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="55" tscDM:imageoffset="0" tscDM:imagerect="125, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  57. Counter (CTR)" xmpDM:startTime="2379000" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="56" tscDM:imageoffset="0" tscDM:imagerect="200, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  58. Advantages and Limitations of OFB" xmpDM:startTime="2381233" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="57" tscDM:imageoffset="0" tscDM:imagerect="275, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  59. Counter (CTR)" xmpDM:startTime="2438700" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="58" tscDM:imageoffset="0" tscDM:imagerect="350, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  60. Advantages and Limitations of OFB" xmpDM:startTime="2496033" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="59" tscDM:imageoffset="0" tscDM:imagerect="425, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  61. Counter (CTR)" xmpDM:startTime="2515733" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="60" tscDM:imageoffset="0" tscDM:imagerect="500, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  62. Advantages and Limitations of CTR" xmpDM:startTime="2685100" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="61" tscDM:imageoffset="0" tscDM:imagerect="575, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  63. Counter (CTR)" xmpDM:startTime="2724800" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="62" tscDM:imageoffset="0" tscDM:imagerect="650, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  64. Advantages and Limitations of CTR" xmpDM:startTime="2753600" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="63" tscDM:imageoffset="0" tscDM:imagerect="725, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  65. Storage Encryption" xmpDM:startTime="2776600" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="64" tscDM:imageoffset="0" tscDM:imagerect="800, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  66. Storage Encryption (Cont)" xmpDM:startTime="2778167" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="65" tscDM:imageoffset="0" tscDM:imagerect="875, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  67. Storage Encryption" xmpDM:startTime="2780867" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="66" tscDM:imageoffset="0" tscDM:imagerect="950, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  68. Advantages and Limitations of CTR" xmpDM:startTime="2781600" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="67" tscDM:imageoffset="0" tscDM:imagerect="1025, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  69. Counter (CTR)" xmpDM:startTime="2877367" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="68" tscDM:imageoffset="0" tscDM:imagerect="1100, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  70. Advantages and Limitations of CTR" xmpDM:startTime="2895933" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="69" tscDM:imageoffset="0" tscDM:imagerect="1175, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  71. Storage Encryption" xmpDM:startTime="2898800" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="70" tscDM:imageoffset="0" tscDM:imagerect="1250, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  72. Storage Encryption (Cont)" xmpDM:startTime="3623800" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="71" tscDM:imageoffset="0" tscDM:imagerect="1325, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  73. Storage Encryption" xmpDM:startTime="3717233" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="72" tscDM:imageoffset="0" tscDM:imagerect="1400, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  74. Advantages and Limitations of CTR" xmpDM:startTime="3717600" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="73" tscDM:imageoffset="0" tscDM:imagerect="1475, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  75. Counter (CTR)" xmpDM:startTime="3717833" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="74" tscDM:imageoffset="0" tscDM:imagerect="1550, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  76. Advantages and Limitations of OFB" xmpDM:startTime="3718167" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="75" tscDM:imageoffset="0" tscDM:imagerect="1625, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  77. Output Feedback (OFB)" xmpDM:startTime="3718600" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="76" tscDM:imageoffset="0" tscDM:imagerect="1700, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  78. Cipher Feedback (CFB)" xmpDM:startTime="3719267" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="77" tscDM:imageoffset="0" tscDM:imagerect="1775, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  79. Output Feedback (OFB)" xmpDM:startTime="3720833" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="78" tscDM:imageoffset="0" tscDM:imagerect="1850, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  80. Advantages and Limitations of OFB" xmpDM:startTime="3721300" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="79" tscDM:imageoffset="0" tscDM:imagerect="1925, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  81. Counter (CTR)" xmpDM:startTime="3721700" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="80" tscDM:imageoffset="0" tscDM:imagerect="2000, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  82. Advantages and Limitations of CTR" xmpDM:startTime="3722300" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="81" tscDM:imageoffset="0" tscDM:imagerect="2075, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  83. Storage Encryption" xmpDM:startTime="3722767" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="82" tscDM:imageoffset="0" tscDM:imagerect="2150, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  84. Storage Encryption (Cont)" xmpDM:startTime="3723233" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="83" tscDM:imageoffset="0" tscDM:imagerect="2225, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  85. Storage Encryption" xmpDM:startTime="3753833" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="84" tscDM:imageoffset="0" tscDM:imagerect="2300, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  86. Advantages and Limitations of CTR" xmpDM:startTime="3754233" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="85" tscDM:imageoffset="0" tscDM:imagerect="2375, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  87. Counter (CTR)" xmpDM:startTime="3754700" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="86" tscDM:imageoffset="0" tscDM:imagerect="2450, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  88. Advantages and Limitations of CTR" xmpDM:startTime="3763433" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="87" tscDM:imageoffset="0" tscDM:imagerect="2525, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  89. Storage Encryption" xmpDM:startTime="3763900" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="88" tscDM:imageoffset="0" tscDM:imagerect="2600, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  90. Storage Encryption (Cont)" xmpDM:startTime="3764400" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="89" tscDM:imageoffset="0" tscDM:imagerect="2675, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  91. XTS-AES Mode" xmpDM:startTime="3788567" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="90" tscDM:imageoffset="0" tscDM:imagerect="2750, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  92. Advantages and Limitations of XTS-AES" xmpDM:startTime="4105333" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="91" tscDM:imageoffset="0" tscDM:imagerect="2825, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  93. XTS-AES Mode" xmpDM:startTime="4106833" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="92" tscDM:imageoffset="0" tscDM:imagerect="2900, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  94. Storage Encryption (Cont)" xmpDM:startTime="4126000" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="93" tscDM:imageoffset="0" tscDM:imagerect="2975, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  95. Storage Encryption" xmpDM:startTime="4126333" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="94" tscDM:imageoffset="0" tscDM:imagerect="3050, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  96. Advantages and Limitations of CTR" xmpDM:startTime="4126667" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="95" tscDM:imageoffset="0" tscDM:imagerect="3125, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  97. Counter (CTR)" xmpDM:startTime="4127167" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="96" tscDM:imageoffset="0" tscDM:imagerect="3200, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  98. Advantages and Limitations of OFB" xmpDM:startTime="4128133" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="97" tscDM:imageoffset="0" tscDM:imagerect="3275, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="  99. Output Feedback (OFB)" xmpDM:startTime="4128667" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="98" tscDM:imageoffset="0" tscDM:imagerect="3350, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="100. Cipher Feedback (CFB)" xmpDM:startTime="4129200" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="99" tscDM:imageoffset="0" tscDM:imagerect="3425, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="101. Stream Modes of Operation" xmpDM:startTime="4130033" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="100" tscDM:imageoffset="0" tscDM:imagerect="3500, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="102. Cipher Text Stealing (CTS)" xmpDM:startTime="4130467" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="101" tscDM:imageoffset="0" tscDM:imagerect="3575, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="103. Stream Modes of Operation" xmpDM:startTime="4134533" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="102" tscDM:imageoffset="0" tscDM:imagerect="3650, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="104. Cipher Feedback (CFB)" xmpDM:startTime="4134900" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="103" tscDM:imageoffset="0" tscDM:imagerect="3725, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="105. Output Feedback (OFB)" xmpDM:startTime="4135233" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="104" tscDM:imageoffset="0" tscDM:imagerect="3800, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="106. Advantages and Limitations of OFB" xmpDM:startTime="4135567" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="105" tscDM:imageoffset="0" tscDM:imagerect="3875, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="107. Counter (CTR)" xmpDM:startTime="4135933" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="106" tscDM:imageoffset="0" tscDM:imagerect="3950, 56, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="108. Advantages and Limitations of CTR" xmpDM:startTime="4136500" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="107" tscDM:imageoffset="0" tscDM:imagerect="25, 112, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="109. Storage Encryption" xmpDM:startTime="4136867" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="108" tscDM:imageoffset="0" tscDM:imagerect="100, 112, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="110. Storage Encryption (Cont)" xmpDM:startTime="4137367" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="109" tscDM:imageoffset="0" tscDM:imagerect="175, 112, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="111. XTS-AES Mode" xmpDM:startTime="4137733" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="110" tscDM:imageoffset="0" tscDM:imagerect="250, 112, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="112. Advantages and Limitations of XTS-AES" xmpDM:startTime="4206633" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="111" tscDM:imageoffset="0" tscDM:imagerect="325, 112, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="113. XTS-AES Mode" xmpDM:startTime="4298067" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="112" tscDM:imageoffset="0" tscDM:imagerect="400, 112, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="114. Advantages and Limitations of XTS-AES" xmpDM:startTime="4305433" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="113" tscDM:imageoffset="0" tscDM:imagerect="475, 112, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="115. Summary" xmpDM:startTime="4305900" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="114" tscDM:imageoffset="0" tscDM:imagerect="550, 112, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="116. Homework 6" xmpDM:startTime="4308167" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="115" tscDM:imageoffset="0" tscDM:imagerect="625, 112, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="117. Summary" xmpDM:startTime="4309267" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="116" tscDM:imageoffset="0" tscDM:imagerect="700, 112, 75, 56"/></rdf:li><rdf:li><rdf:Description xmpDM:name="118. Homework 6" xmpDM:startTime="4381433" tscDM:image="l_06bco2_Thumbnails.png" tscDM:imageindex="117" tscDM:imageoffset="0" tscDM:imagerect="775, 112, 75, 56"/></rdf:li></rdf:Seq>
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