We present a 2-round protocol to prove knowledge of a plaintext corresponding to a given ciphertext. Our protocol is black-box in the underlying cryptographic primitives and it can be instantiated with almost any fully homomorphic encryption scheme. Since our protocol is only 2 rounds it cannot be zero-knowledge [GO94]; instead, we prove that our protocol ensures the semantic security of the underlying ciphertext. To illustrate the merit of this relaxed proof of knowledge property, we use our result to construct a secure multi-party computation protocol for evaluating a function f in the standard model using only black-box access to a threshold fully homomorphic encryption scheme. This protocol requires communication that is independent of |f|; while Gentry [Gen09a] has previously shown how to construct secure multi-party protocols with similar communication rates, the use of our novel primitive (along with other new techniques) avoids the use of complicated generic white-box techniques (cf. PCP encodings [Gen09a] and generic zero-knowledge proofs [AJLA+12, LATV11].) In this sense, our work demonstrates in principle that practical TFHE can lead to reasonably practical secure computation. © 2013 International Association for Cryptologic Research.
CITATION STYLE
Myers, S., Sergi, M., & Shelat, A. (2013). Black-box proof of knowledge of plaintext and multiparty computation with low communication overhead. In Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) (Vol. 7785 LNCS, pp. 397–417). https://doi.org/10.1007/978-3-642-36594-2_23
Mendeley helps you to discover research relevant for your work.