Square Attack on Reduced Camellia Cipher

Camellia block cipher, which is 128-bit block size and supports 128-, 192- and 256-bit keys, is one of the NESSIE (New European Schemes for Signatures, Integrity and Encryption) candidates. The Square attack on Camellia is studied in this paper. With the detail analysis of round function in Camellia, Square attack extension to 6 rounds faster than exhaustive key search was found. The result of the paper shows that Square attack is the best attack on Camellia.