FROG - Definition and Overview

In cryptography, FROG is a block cipher authored by Georgoudis, Leroux and Chaves. The algorithm can work with any block size between 8 and 128 bytes, and supports keys sizes betweens 5 and 125 bytes. The algorithm consists of 8 rounds and has a very complicated key schedule.

It was submitted in 1998 to the AES competition as a candidate to become the Advanced Encryption Standard. Wagner et al (1999) found a number of weak key classes for FROG. Other problems included the very slow key setup and the relatively slow encryption. FROG was not selected as a finalist.

References

• David Wagner, Niels Ferguson and Bruce Schneier, Cryptanalysis of FROG, in proceedings of the 2nd AES candidate conference, pp175–181, NIST, 1999 [1] (http://www.schneier.com/paper-frog.html).
• Dianelos Georgoudis, Damian Leroux and Billy Simón Chaves, The FROG Encryption Algorithm, June 15, 1998 [2] (http://www.tecapro.com/aesfrog.html).