LOKI97

In cryptography, LOKI97 is a block cipher which was a candidate in the Advanced Encryption Standard competition. It is a member of the LOKI family of ciphers, earlier instances being LOKI89 and LOKI91. LOKI97 was designed by Lawrie Brown, assisted by Jennifer Seberry and Josef Pieprzy.

Like DES, LOKI97 is a 16-round Feistel cipher, and like other AES candidates, has a 128-bit block size and a choice of a 128-, 192- or 256-bit key length. The key schedule is also a Feistel structure — an unbalanced one unlike the main network — but using the same F-function.

The authors have stated that, "LOKI97 is a non-proprietary algorithm, available for royalty-free use worldwide as a possible replacement for the DES or other existing block ciphers."

References

• L. Brown, J. Pieprzyk: Introducing the new LOKI97 Block Cipher
• L.R. Knudsen and V. Rijmen, "Weaknesses in LOKI97", Proceedings of the 2nd AES Candidate Conference , Rome, March 22-23, 1999, pp. 168–174.