Usr6 Posted May 19, 2018 Report Posted May 19, 2018 Photonic Side Channel Attacks Against RSA Elad Carmon, Jean-Pierre Seifert, Avishai Wool Abstract This paper describes the first attack utilizing the photonic side channel against a public-key crypto-system. We evaluated three common implementations of RSA modular exponentiation, all using the Karatsuba multiplication method. We discovered that the key length had marginal impact onresilience to the attack: attacking a 2048-bit key required only 9% more decryption attempts than a 1024-bit key. We found that the most dominant parameter impacting the attacker’s effort is the minimal block size at which the Karatsuba method reverts to naive multiplication: even for parameter values as low as 32 or 64 bits our attacks achieve 100% success rate with under 10,000 decryption operations. Somewhat surprisingly, we discovered that Montgomery’s Ladder—commonly perceived as the most resilient of the three implementations to side-channel attacks—was actually the most susceptible: for 2048-bit keys, our attack reveals 100% of the secret key bits with as few as 4000 decryptions. Link: https://eprint.iacr.org/2017/108.pdf 3 Quote
