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Results tagged with des
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user 42494
(or Data Encryption Standard), a (symmetric) block cipher using a 64 bit block size, with keys of size 56 bit, the standard US block cipher from 1976 to 2001.
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DES and Feistel Cipher
The DES "expansion permutation" is called a permutation, because it rearranges bits, but it is not a permutation at all, because it copies bits as well. … Since DES is encryption is essentially a sequence of Feistel rounds, it can be decrypted by performing the same Feistel operations in reverse order. …
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