A Linearly Homomorphic Signature Scheme from Weaker Assumptions

Title

A Linearly Homomorphic Signature Scheme from Weaker Assumptions

Authors

Lucas¬†Schabh√ľser,¬†Johannes¬†Buchmann,¬†Patrick¬†Struck

Abstract

In delegated computing, prominent in the context of cloud computing, guaranteeing both the correctness and authenticity of computations is of critical importance. Homomorphic signatures can be used as cryptographic solutions to this problem. In this paper we solve the open problem of constructing a linearly homomorphic signature scheme that is secure against an active adversary under standard assumptions. We provide a construction based on the DL and CDH assumption. Furthermore we show how our scheme can be combined with homomorphic encryption under the framework of Linearly Homomorphic Authenticated Encryption with Public Verifiability. This way we can provide the first such scheme that is context hiding. Furthermore our solution even allows verification in constant time (in an amortized sense).

Venue

IMA International Conference on Cryptography and Coding (IMACC 2017)

Place and Date

12 - 14 December 2017, Oxford, UK

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