Unit 3-Symmetric Key Crypto_Part13

# Unit 3-Symmetric Key Crypto_Part13 - To encrypt, the...

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Unit 3 - 25 Block Ciphers An iterated block cipher splits the plaintext into fixed sized blocks and generates fixed sized blocks of ciphertext. The ciphertext is obtained from the plaintext by iterating a function F over some number of rounds. The function F , which depends on the output of the previous round and the key K , is known as a round function . Usually implemented in software.

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Unit 3 - 26 Feistel Cipher A Feistel cipher was developed by Horst Feistel. Feistel, is a general cipher design principle, not a specific cipher
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Unformatted text preview: To encrypt, the plaintext P is split into left and right halves, For each round i = 1, 2, . . . , n new left and right halves are computed according to the rule K i is the subkey for round i . The subkey is derived from the key K according to a key schedule algorithm . Finally, the ciphertext C is the output of the final round P = (L , R ) L i = R i −1 R i = L i −1 ⊕ F(R i −1 , K i ) C = (L n , R n )...
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## This note was uploaded on 03/17/2011 for the course ECE 4472 taught by Professor Ouda during the Fall '10 term at UWO.

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Unit 3-Symmetric Key Crypto_Part13 - To encrypt, the...

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