- Nimbus (cipher)
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This article is about the block cipher. For other uses, see Nimbus (disambiguation).
Nimbus General Designers Alexis Machado First published 2000 Cipher detail Key sizes 128 bits Block sizes 64 bits Rounds 5 Best public cryptanalysis Differential cryptanalysis can break Nimbus with 256 chosen plaintexts. In cryptography, Nimbus is a block cipher invented by Alexis Machado in 2000. It was submitted to the NESSIE project, but was not selected.
The algorithm uses a 128-bit key. It operates on blocks of 64 bits and consists of 5 rounds of encryption. The round function is exceedingly simple. In each round the block is XORed with a subkey, the order of its bits is reversed, and then it is multiplied mod 264 by another subkey, which is forced to be odd.
Nimbus was broken by Vladimir Furman; he found a differential attack using only 256 chosen plaintexts.
References
- Security evaluation of NESSIE first phase (PDF)
- Eli Biham, Vladimir Furman (November 29, 2000) (PDF/PostScript). Differential Cryptanalysis of Nimbus. http://citeseer.ist.psu.edu/biham00differential.html. Retrieved February 8, 2007.
Categories:- Block ciphers
- Cryptography stubs
- Broken block ciphers
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