Verifiable secret sharing

About: Verifiable secret sharing is a research topic. Over the lifetime, 4241 publications have been published within this topic receiving 99569 citations.

VKSE-MO: verifiable keyword search over encrypted data in multi-owner settings

Abstract: Searchable encryption (SE) techniques allow cloud clients to easily store data and search encrypted data in a privacy-preserving manner, where most of SE schemes treat the cloud server as honest-but-curious. However, in practice, the cloud server is a semi-honest-but-curious third-party, which only executes a fraction of search operations and returns a fraction of false search results to save its computational and bandwidth resources. Thus, it is important to provide a results verification method to guarantee the correctness of the search results. Existing SE schemes allow multiple data owners to upload different records to the cloud server, but these schemes have very high computational and storage overheads when applied in a different but more practical setting where each record is co-owned by multiple data owners. To address this problem, we develop a verifiable keyword search over encrypted data in multi-owner settings (VKSE-MO) scheme by exploiting the multisignatures technique. Thus, our scheme only requires a single index for each record and data users are assured of the correctness of the search results in challenging settings. Our formal security analysis proved that the VKSE-MO scheme is secure against a chosen-keyword attack under a random oracle model. In addition, our empirical study using a real-world dataset demonstrated the efficiency and feasibility of the proposed scheme in practice.

Introduction to Secure Computation

Abstract: The objective of this paper is to give an elementary introduction to fundamental concepts, techniques and results of Secure Computation. Topics covered include classical results for general secure computation by Yao, Goldreich & Micali & Wigderson, Kilian, Ben-Or & Goldwasser & Wigderson, and Chaum & CrEpeau & Damgaard. We also introduce such concepts as oblivious transfer, security against malicious attacks and verifiable secret sharing, and for some of these important primitives we discuss realization. This paper is organized as follows. Part I deals with oblivious transfer and secure (general) two-party computation. Part II discusses secure general multi-party computation and verifiable secret sharing. Part III addresses information theoretic security and presents detailed but elementary explanations of some recent results in Verifiable Secret Sharing and Multi-Party Computation. The importance of theory and general techniques often lies in the fact that the true nature of security is uncovered and that this henceforth enables to explore what is "possible at all". This then motivates the search for concrete and often specialized realizations that are more efficient. Nevertheless, many principles developed as part of the general theory are fundamental to the design of practical solutions as well.

Asynchronous Distributed Key Generation for Computationally-Secure Randomness, Consensus, and Threshold Signatures.

Abstract: In this paper, we present the first Asynchronous Distributed Key Generation (ADKG) algorithm which is also the first distributed key generation algorithm that can generate cryptographic keys with a dual (f,2f+1)-threshold (where f is the number of faulty parties). As a result, using our ADKG we remove the trusted setup assumption that the most scalable consensus algorithms make. In order to create a DKG with a dual (f,2f+1)- threshold we first answer in the affirmative the open question posed by Cachin et al. [7] on how to create an Asynchronous Verifiable Secret Sharing (AVSS) protocol with a reconstruction threshold of f+1

Verifier-on-a-Leash: New Schemes for Verifiable Delegated Quantum Computation, with Quasilinear Resources

Abstract: The problem of reliably certifying the outcome of a computation performed by a quantum device is rapidly gaining relevance. We present two protocols for a classical verifier to verifiably delegate a quantum computation to two non-communicating but entangled quantum provers. Our protocols have near-optimal complexity in terms of the total resources employed by the verifier and the honest provers, with the total number of operations of each party, including the number of entangled pairs of qubits required of the honest provers, scaling as \(O(g\log g)\) for delegating a circuit of size g. This is in contrast to previous protocols, whose overhead in terms of resources employed, while polynomial, is far beyond what is feasible in practice. Our first protocol requires a number of rounds that is linear in the depth of the circuit being delegated, and is blind, meaning neither prover can learn the circuit or its input. The second protocol is not blind, but requires only a constant number of rounds of interaction.