International Association for Cryptologic Research

International Association
for Cryptologic Research

CryptoDB

Yevgeniy Vahlis

Affiliation: AT&T

Publications

Year
Venue
Title
2012
PKC
2011
TCC
2011
CRYPTO
2010
TCC
2010
EPRINT
On Protecting Cryptographic Keys Against Continual Leakage
Ali Juma Yevgeniy Vahlis
Side-channel attacks have often proven to have a devastating effect on the security of cryptographic schemes. In this paper, we address the problem of storing cryptographic keys and computing on them in a manner that preserves security even when the adversary is able to obtain information leakage during the computation on the key. Using the recently achieved fully homomorphic encryption, we show how to encapsulate a key and repeatedly evaluate arbitrary functions on it so that no adversary can gain any useful information from a large class of side-channel attacks. We work in the model of Micali and Reyzin, assuming that only the active part of memory during computation leaks information. Similarly to previous works, our construction makes use of a single ``leak-free'' hardware token that samples from a globally-fixed distribution that does not depend on the key. Our construction is the first general compiler to achieve resilience against polytime leakage functions without performing any leak-free computation on the underlying secret key. Furthermore, the amount of computation our construction must perform does not grow with the amount of leakage the adversary is able to obtain; instead, it suffices to make a stronger assumption about the security of the fully homomorphic encryption.
2010
CRYPTO
2008
EPRINT
CCA2 Secure IBE: Standard Model Efficiency through Authenticated Symmetric Encryption
Eike Kiltz Yevgeniy Vahlis
We propose two constructions of chosen-ciphertext secure identity-based encryption (IBE) schemes. Our schemes have a security proof in the standard model, yet they offer performance competitive with all known random-oracle based schemes. The efficiency improvement is obtained by combining modifications of the IBE schemes by Waters and Gentry with authenticated symmetric encryption.

Program Committees

PKC 2014