We address the problem of compiling any circuit into a circuit secure against OCL attacks. In order to leverage the OCL assumption, the resulting circuit will be split into components, where at any point in time only a single component is active. Optimally, we would like to output a circuit that has only one component, and no part of the computation needs to be leak-free. However, this task is impossible due to the result of Barak et al. [JACM '12].The current state-of-the-art constructions achieve either two components with additional leak-free hardware, or many components without leak-free hardware.
In this work, we show how to achieve the best of both worlds: We construct two-component OCL schemes without relying on leak-free components. Our approach is general and modular -- we develop generic techniques to remove the hardware component from hardware-based constructions, when the functionality provided by the hardware satisfies some properties. Our techniques use universal deniable encryption (recently constructed by Sahai and Water [STOC '14] using indistinguishable obfuscation) and non-committing encryption in a novel way. Then, we observe that the functionalities of the hardware used in previous two-component constructions of Juma and Vahlis [Crypto '10], and Dziembowski and Faust [TCC '12] satisfy the required properties.
The techniques developed in this paper have deep connections with adaptively secure and leakage tolerant multi-party computation (MPC). Our constructions immediately yield adaptively secure and leakage tolerant MPC protocols for any no-input randomized functionality in the semi-honest model. The result holds in the CRS model, without pre-processing. Our results also have implications to two-party leakage tolerant computation for arbitrary functionalities, which we obtain by combining our constructions with a recent result of Bitansky, Dachman-Soled, and Lin [Crypto '14].Category / Keywords: foundations / Leakage resilience, OCL, Leakage Tolerant Computation, Adaptive Security Date: received 19 Oct 2014 Contact author: fenghao at cs umd edu Available format(s): PDF | BibTeX Citation Version: 20141022:181652 (All versions of this report) Short URL: ia.cr/2014/856 Discussion forum: Show discussion | Start new discussion