Practical fully leakage resilient signatures with auxiliary inputs

【Author】 Cai, Cailing; Pan, Shimin; Yuen, Tsz Hon; Yiu, Siu-Ming

【Source】FUTURE GENERATION COMPUTER SYSTEMS-THE INTERNATIONAL JOURNAL OF ESCIENCE

【影响因子】7.307

【Abstract】Digital signatures are essential techniques used in the real world, especially for validating the authenticity of a given message. The security of the digital signatures based on the traditional security definition, however, may be vulnerable to the side-channel attacks. Currently, although several leakage -resilient signature (LR-Sig) schemes have been proposed to model the side-channel attacks, the schemes are highly inefficient. Because either the signature size is quite large or a limited fraction of the secret key can be leaked. In this paper, we present practical LR-Sig schemes that are able to withstand a large scale of leakage.Technically, we build the first generic construction of LR-Sig, which is secure in the auxiliary input model (allowing leakage by any hard-to-invert function), continual memory leakage (updating the secret key periodically while remaining the public key fixed) and fully leakage resilience (admitting leakage of the secret key and the signing randomness). Apart from the strong security model, the sizes of our signature and public key are the same as each underlying standard signature scheme. In particular, the verification algorithm of our LR-Sig is as fast as the original scheme. Thereby, our instantiation LR-ECDSA can be easily adopted in the existing cryptocurrencies since no additional modification is needed for the verifier side. Furthermore, we provide the first comprehensive quantitative analysis for different LR-Sig schemes. The state-of-the-art signature schemes, which are able to leak over 50% of the secret key, are at least 565k bits. Comparatively, our shortest instantiation LR-BLS has a signature size of only 1 group element (382 bits, shorten by 1479 times) regardless of the percentage of leakage. Meanwhile, our LR-BLS is also the first deterministic LR-Sig. Besides, our instantiation LR-Schnorr enjoys the fastest verification.(c) 2022 Elsevier B.V. All rights reserved.

【Keywords】Leakage resilient signature; Auxiliary input model; Continual memory leakage; Side -channel attacks

【发表时间】2023 APR

【收录时间】2023-01-14

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