Diapositiva%201

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The OCB1
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The OCB1 (Contd.)
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Instantiation of OCB1 with a XEX blockcipher
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The PMAC Algorithm
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The PMAC Algorithm (contd.)
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The PMAC Algorithm (contd.)
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AEAD Schemes
Using OCB and PMAC for AEAD Let OCB
(K,E,D) Let the message be M and header be
H Obtain Ct E(K, M) Obtain d PMAC(K,H) The
final ciphertext is C(t XOR d)
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AEAD Schemes (cont.)
Rogaway proposed a general way to construct AEAD
schemes from a secure symmetric encryption scheme
and a pseudorandom function These schemes are
called generic composition schemes. Rogaway
suggests two ways Mac then Encrypt Encrypt
then Mac
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Generic Composition Encrypt then Mac
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Generic Composition Mac then Encrypt
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The CMC Mode of Operation
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Encryption and decryption using CMC
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The EME Mode of Operation
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Encryption and decryption using EME
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HCTR Mode of operation
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HCTR Mode of operation
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HCTR Mode of operation
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PEP Mode of Operation