SPEAKER: Yevgeniy Vahlis TITLE: Cryptography in The Presence of Continuous Side-Channel Attacks AUTHORS: Ali Juma, Charles Rackoff and Yevgeniy Vahlis ABSTRACT: Recent trends in computing increasingly rely on delegating computation both to centralized cloud computing environments, and to mobile computers such as smart cards and mobile phones. This creates new security risks and consequently new challenges for cryptography. One such challenge stems from the fact that physical computational devices leak information to the outside world through a variety of side-channels-- physical characteristics of the device such as power consumption, electromagnetic radiation, and timing. An attacker that has physical possession of the device, or is within a short distance, may use this information to learn about the internal state of the device and about the computation that is currently being performed. Such side-channel attacks have often been shown to break the security of widely used cryptographic schemes without violating any of the mathematical assumptions that underly the security of the scheme. In this talk I will present a general compiler that immunizes any cryptographic functionality against long-term leakage through side-channels. Our construction uses a single leak-free hardware component and any fully homomorphic encryption scheme with randomizable ciphertexts. The hardware component samples from a publicly known distribution which does not depend on the functionality that we wish to protect or its internal state. We prove the security of our construction against an adversary that obtains leakage each time the cryptographic functionality is used. The information leaked can be any suitably length-bounded polynomial time computable function of the active part of memory during computation. The total amount of leakage that the construction can withstand is unbounded. Our construction constitutes a first feasibility result, showing that resilience against polynomial time leakage is possible without performing any leak-free computation on the state of the protected primitive. However, many directions remain open. I will describe several such directions, and mention recent progress. Joint work with Ali Juma and Charles Rackoff. LINKS: The bulk of the results can also be found here at http://eprint.iacr.org/2010/205