Provably Secure and E cient Block Ciphers
نویسنده
چکیده
The security and eciency of two recently proposed block ciphers, bear and lion, both based on a hash function and a stream cipher, is discussed. Meet-in-the-middle attacks are presented which can be used to dramatically reduce the complexity of a brute-force key search on both these ciphers. A new block cipher is described which is not susceptible to meet-in-the-middle attacks, is provably secure against any chosen plaintext or ciphertext attack, and is more eecient than bear or lion.
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Two Practical and Provably Secure Block Ciphers: BEAR and LION
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