The Leakage-Resilience Limit of a Computational Problem Is Equal to Its Unpredictability Entropy

A cryptographic assumption is the (unproven) mathematical statement that a certain computational problem (e.g. factoring integers) is computationally hard. The leakage-resilience limit of a cryptographic assumption, and hence of a computational search problem, is the maximal number of bits of information that can be leaked (adaptively) about an instance, without making the problem easy to solve. This implies security of the underlying scheme against arbitrary side channel attacks by a computationally unbounded adversary as long as the number of leaked bits of information is less than the leakage resilience limit. The hardness of a computational problem is typically characterized by the running time of the fastest (known) algorithm for solving it. We propose to consider, as another natural complexity-theoretic quantity, the success probability of the best polynomial-time algorithm (which can be exponentially small). We refer to its negative logarithm as the unpredictability entropy of t...

• Type: Journal
• Year: 2011
• Where: ASIACRYPT
• Authors: Divesh Aggarwal, Ueli Maurer
• Keywords: ASIACRYPT 2011, Cryptology, Lattice Problems, Polynomial Time Algorithm, Probabilistic Polynomial