Leakage-Resilient Public-Key Cryptography in the Bounded-Retrieval Model

We study the design of cryptographic primitives resilient to key-leakage attacks, where an attacker can repeatedly and adaptively learn information about the secret key, subject only to the constraint that the overall amount of such information is bounded by some parameter . We construct a variety of leakage-resilient public-key systems including the first known identification schemes (ID), signature schemes and authenticated key agreement protocols (AKA). Our main result is an efficient three-round leakage-resilient AKA in the Random-Oracle model. This protocol ensures that session keys are private and authentic even if (1) the adversary leaks a large fraction of the long-term secret keys of both users prior to the protocol execution and (2) the adversary completely learns the long-term secret keys after the protocol execution. In particular, our AKA protocol provides qualitatively stronger privacy guarantees than leakage-resilient public-encryption schemes (constructed in prior an...

• Type: Conference
• Year: 2009
• Where: CRYPTO
• Authors: Joël Alwen, Yevgeniy Dodis, Daniel Wichs
• Keywords: CRYPTO 2009, Cryptology, Long-term Secret Keys, Protocol Execution, Secret Key