General | |
---|---|
Designers | NTT |
First published | 1998 |
Successors | Camellia |
Cipher detail | |
Key sizes | 128, 192, or 256 bits |
Block sizes | 128 bits |
Structure | Feistel network |
Rounds | 12 |
In cryptography, E2 is a symmetric block cipher which was created in 1998 by NTT and submitted to the AES competition.
Like other AES candidates, E2 operates on blocks of 128 bits, using a key of 128, 192, or 256 bits. It uses a 12-round Feistel network. E2 has an input transformation and output transformation that both use modular multiplication, but the round function itself consists only of XORs and S-box lookups. The single 8×8-bit S-box is constructed from the composition of an affine transformation with the discrete exponentiation x over the finite field GF(2). NTT adopted many of E2's special characteristics in Camellia, which has essentially replaced E2.
References
- M. Matsui, T. Tokita (March 1999). Cryptanalysis of a Reduced Version of the Block Cipher E2 (PDF). 6th International Workshop on Fast Software Encryption (FSE 1999). Rome: Springer-Verlag. pp. 71–80. doi:10.1007/3-540-48519-8_6. Retrieved 27 February 2007.