Differential Cryptanalysis of a Reduced-Round SEED
نویسندگان
چکیده
We analyze the security of the SEED block cipher against di erential attacks. SEED is a 16-round Feistel cipher developed by the Korea Information Security Agency. The SEED proposers estimated their cipher against di erential cryptanalysis in a self-estimation document and found a six-round di erential characteristic with probability 2 130 . We present an improved method of examining the di erential characteristics of SEED and show three six-round di erential characteristics with probability 2 124 . These characteristics allow us to attack seven-round SEED, which surpasses the proposers estimation. Our di erential attack needs 2 126 chosen-plaintext pairs and 2 126 computations of the F function to deduce the subkey used in the last round of seven-round SEED.
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