International Association for Cryptologic Research

International Association
for Cryptologic Research

CryptoDB

Markus Dürmuth

Publications

Year
Venue
Title
2011
EUROCRYPT
2009
EPRINT
A Provably Secure And Efficient Countermeasure Against Timing Attacks
Boris Köpf Markus Dürmuth
We show that the expected number of key bits that an unknown-message attacker can extract from a deterministic side-channel is bounded from above by |O| log_2 (n+1), where n is the number of side-channel measurements and O is the set of possible observations. We use this bound to derive a novel countermeasure against timing attacks, where the strength of the security guarantee can be freely traded for the resulting performance penalty. We give algorithms that efficiently and optimally adjust this trade-off for given constraints on the side-channel leakage or on the efficiency of the cryptosystem. Finally, we perform a case-study that shows that applying our countermeasure leads to implementations with minor performance overhead and strong security guarantees.

Coauthors

David Freeman (1)
Boris Köpf (1)