New Impossible Differential Attack on SAFER+ and SAFER++
SAFER+ was a candidate block cipher for AES with 128-bit block size and variable key sizes of 128, 192 or 256 bits. Bluetooth uses customized versions of SAFER+ for security. The numbers of rounds for SAFER+ with key sizes of 128, 192 and 256 are 8, 12 and 16, respectively. SAFER++, a variant of SAFER+, was among the cryptographic primitives selected for the second phase of the NESSIE project. The block size is 128 bits and the key size can take either 128 or 256 bits. The number of rounds is 7 for SAFER++ /128 and 10 for SAFER++ /256. Both ciphers use PHT as their linear transformations.