Camellia (cipher)

Camellia is a symmetric block cipher that was developed in 2000 in collaboration between Mitsubishi and NTT. Camellia was selected by the European NESSIE project, and the Japanese CRYPTREC project as one of their recommended algorithms. Camellia has similarities with the algorithms Misty1 and E2, which were previously developed by these companies.

Camellia uses the same parameters as the Advanced Encryption Standard: a block size of 128 bits and key lengths of 128, 192 or 256 bits. It is a Feistelchiffre with SPN round function. The number of rounds depends on the key length - 18 rounds with 128-bit or 24 laps with longer keys. As a non- linear substitution layer serve four 8 × 8- bit S-boxes with large affine transformations and logical XOR, which emerge through rotations around a bit from. The Permutationsschicht used only linear transformations and is similar to the P- function of E2. To complicate bitwise cryptanalysis, in addition, all six rounds is applied to an ajar MISTY linear FL- function on the left half- block and its inverse FL -1 on the right half- block.