A novel methodology for analysis of the computational complexity of block ciphers: Rijndael, Camellia and Shacal-2 compared.

The paper presents a methodology for the evaluation of the complexity and computational cost of different block ciphers, in order to be independent from the actual platforms they are implemented on. An analysis of three block ciphers selected by NESSIE (New European Schemes for Signatures, Integrity and Encryption) in 2003 - Rijndael, Camellia and Shacal-2 - is then provided using such methodology. First, the structure of all ciphers is described, so as to emphasize the different kinds of transformations required. Then, the schemes are compared in terms of basic operations (AND, OR, shifts) for each step, in such a way to evaluate their complexity and to provide effective guidelines regarding their implementation.