## Cryptology ePrint Archive: Report 2017/926

How to Construct a Leakage-Resilient (Stateless) Trusted Party

Daniel Genkin and Yual Ishai and Mor Weiss

Abstract: Trusted parties and devices are commonly used in the real world to securely perform computations on secret inputs. However, their security can often be compromised by side-channel attacks in which the adversary obtains partial leakage on intermediate computation values. This gives rise to the following natural question: To what extent can one protect the trusted party against leakage?

Our goal is to design a hardware device $T$ that allows $m\ge 1$ parties to securely evaluate a function $f(x_1,\ldots,x_m)$ of their inputs by feeding $T$ with encoded inputs that are obtained using local secret randomness. Security should hold even in the presence of an active adversary that can corrupt a subset of parties and obtain restricted leakage on the internal computations in $T$.

We design hardware devices $T$ in this setting both for zero-knowledge proofs and for general multi-party computations. Our constructions can unconditionally resist either $AC^0$ leakage or a strong form of only computation leaks'' (OCL) leakage that captures realistic side-channel attacks, providing different tradeoffs between efficiency and security.

Category / Keywords: Leakage-Resilience, Secure Multiparty Computation, Algebraic Manipulation Detection, AMD Circuits

Original Publication (with major differences): IACR-TCC-2017

Date: received 19 Sep 2017, last revised 4 Dec 2017

Contact author: mormorweiss at gmail com

Available format(s): PDF | BibTeX Citation

Short URL: ia.cr/2017/926

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