A Cache Trace Attack On Camellia

CAMELLIA is a 128 bit block cipher certified for its security by NESSIE and CRYPTREC. Yet an implementation of CAMELLIA can easily fall prey to cache attacks. In this paper we present an attack on CAMELLIA, which utilizes cache access patterns along with the differential properties of CAMELLIA's s-boxes. The attack, when implemented on a PowerPC microprocessor having a 32 byte cache line size requires power traces from 2(16) different encryptions. Further, the work shows that this trace requirement reduces to 2(11) if a 64 byte cache line is used.