SXAL/MBAL
Block cipher / From Wikipedia, the free encyclopedia
In cryptography, SXAL (substitution xor algorithm, sometimes called SXAL8) is a block cipher designed in 1993 by Yokohama-based Laurel Intelligent Systems. It is normally used in a special mode of operation called MBAL (multi-block algorithm). SXAL/MBAL has been used for encryption in a number of Japanese PC cards and smart cards.
General | |
---|---|
Designers | Laurel Intelligent Systems |
First published | December 1993 |
Cipher detail | |
Key sizes | 64 bits |
Block sizes | 64 bits |
Structure | Substitution–permutation network |
Rounds | 8 |
Best public cryptanalysis | |
Differential and linear cryptanalysis[1] |
SXAL is an 8-round substitution–permutation network with block size and key size of 64 bits each. All operations are byte-oriented. The algorithm uses a single 8×8-bit S-box K, designed so that both K(X) and X XOR K(X) are injective functions. In each round, the bytes of the block are first permuted. Then each byte is XORed with a key byte and an earlier ciphertext byte, processed through the S-box, and XORed with the previous plaintext byte.
The key schedule is rather complex, processing the key with SXAL itself, beginning with a null key and using permuted intermediate results as later keys.