Insured MPC: Efficient Secure Computation with Financial Penalties
Insured MPC: Efficient Secure Computation with Financial Penalties
复制标题
受保险的 MPC：高效安全计算并带来经济处罚
DOI：
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
Rafael Dowsley
中科院分区：
文献类型：
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作者：
Carsten Baum;B. David;Rafael Dowsley
众所周知，在不诚实的多数存在的情况下，安全多方计算（MPC）中的公平性是不可能实现的。以前的工作已经提出将MPC协议与加密货币结合起来，以便在经济上惩罚放弃的对手，为各方诚实地遵循协议提供激励。现有工作的重点是证明这种方法是可能的，不幸的是，它们呈现的是单一的、低效的结构。在这项工作中，我们提出了“投保MPC”的第一个UC安全模块化结构，其中私人计算的输出（描述如何分配资金）是公平交付的，或者是一组当事人行为不当的证明，允许经济惩罚。此外，输出和作弊证明都是可公开验证的，允许第三方独立验证执行。我们提出了一个高效的编译器，该编译器从具有某些属性的MPC协议，标准（非私有）智能合约和可公开验证的同态承诺方案中实现保险MPC。作为中间步骤，我们首先提出了一个具有可组合性保证的公开可验证同态承诺方案的构造。
Fairness in Secure Multiparty Computation (MPC) is known to be impossible to achieve in the presence of a dishonest majority. Previous works have proposed combining MPC protocols with cryptocurrencies in order to financially punish aborting adversaries, providing an incentive for parties to honestly follow the protocol. The focus of existing work is on proving that this approach is possible and unfortunately they present monolithic and mostly inefficient constructions. In this work, we put forth the first UC secure modular construction of “Insured MPC”, where either the output of the private computation (which describes how to distribute funds) is fairly delivered or a proof that a set of parties has misbehaved is produced, allowing for financial punishments. Moreover, both the output and the proof of cheating are publicly verifiable, allowing third parties to independently validate an execution. We present an efficient compiler that implements Insured MPC from an MPC protocol with certain properties, a standard (non-private) Smart Contract and a publicly verifiable homomorphic commitment scheme. As an intermediate step, we propose the first construction of a publicly verifiable homomorphic commitment scheme with composability guarantees.