Docteur en Sciences Appliquées Composition du jury:

Two very different problems are tackled in this dissertation. In the first part, we analyze new side channels that exploit the memory architecture of current processors; the cache in particular. By nature, the cache mechanism presents different timings in the memory accesses: in the best case, the requested data is held by the cache and the access time is short (cache-hit), otherwise the data must be fetched from a higher memory level and the access time is longer (cache-miss). In cache-based attacks, a program with some secret data is executed and an attacker exploits the timing differences in order to discover this secret data. New cache-based side channel attacks are presented for AES and software countermeasures are given. The second part presents our analysis of spam mail. The purpose is to quantify the effectiveness of email address protections against the gathering tools and techniques of spammers. With the help of interconnecte