Hardware Prefetchers Leak: A Revisit of SVF for Cache-Timing Attacks

Micro-architectural features have an influence on security against cache attacks. This paper shows that modern hardware prefetchers enabled in cache memories to reduce the miss penalty, can be a source of information leakage with respect to cache-timing attacks. The work revisits the Side Channel Vulnerability Factor (SVF) proposed in ISCA¿12 and shows how to adapt the metric to assess the vulnerability of a prefetcher in cache-timing attacks. We use the modified metric denoted Timing-SVF, to show that standard prefetchers based on sequential algorithms can leak information in cache timing attacks. The findings have been established by experimental validations on a standard 128 bit cipher, called CLEFIA, designed by Sony Corporation Ltd. and used for light weight cryptography.