KN-Cipher

Infobox block cipher
name = KN-Cipher
designers = Kaisa Nyberg and Lars Knudsen
publish date = 1995
derived from =
derived to =
related to =
certification =
key size = 198 bits
block size = 64 bits
structure = Feistel network
rounds = 6
cryptanalysis = Jakobsen & Knudsen's higher order differential cryptanalysis breaks KN-Cipher with only 512 chosen plaintexts and 2⁴¹ running time, or with 32 chosen plaintexts and 2⁷⁰ running time.In cryptography, KN-Cipher is a block cipher created by Kaisa Nyberg and Lars Knudsen in 1995. One of the first ciphers designed to be provably secure against ordinary differential cryptanalysis, KN-Cipher was later broken using higher order differential cryptanalysis.

Presented as "a prototype...compatible with DES", the algorithm has a 64-bit block size and a 6-round Feistel network structure. The round function is based on the cube operation in the finite field GF(2³³).

The designers didn't specify any key schedule for the cipher; they state, "All round keys should be independent, therefore we need at least 198 key bits."

References

* cite journal
author = K. Nyberg, L.R. Knudsen
title = Provable Security Against a Differential Attack
journal = Journal of Cryptology
volume = 8
issue = 1
issn = 0933-2790
pages = pp.27–37
date = 1995
url = http://citeseer.ist.psu.edu/nyberg95provable.html
format = PDF/PostScript
accessdate = 2007-01-23
* cite conference
author = T. Jakobsen, L.R. Knudsen
title = The Interpolation Attack on Block Ciphers
booktitle = 4th International Workshop on Fast Software Encryption (FSE '97)
pages = pp.28–40
publisher = Springer-Verlag
date = January 1997
location = Haifa
url = http://citeseer.ist.psu.edu/jakobsen97interpolation.html
format = PDF/PostScript
accessdate = 2007-01-23