可公开验证的隐蔽安全的MPC友好承诺
MPC-Friendly Commitments for Publicly Verifiable Covert Security
摘要：
我们解决的问题，有效地验证一个承诺在两方计算。这解决了一方P1向另一方P2提交要在随后的安全计算中使用的值$x$的情况，另一方P2想要接收P1没有欺骗的保证，即$x$确实是输入到安全计算中的值。我们的构造在可公开验证的隐蔽（PVC）安全模型中运行，这是MPC恶意模型的放松，适用于P1如果被发现作弊将面临声誉损害的环境。我们引入PVC承诺方案和索引哈希函数的概念，以建立专门针对PVC框架的承诺方案，并提出了算术和布尔电路的结构，从而产生非常有效的电路。从实用的角度来看，我们的布尔电路的结构是$60\times$更快的安全评估，并使用$36\times$更少的通信比基线方法的基础上散列。此外，我们表明，我们的结构是紧的所需的非线性操作，通过证明下界的非线性门数的承诺验证电路。最后，我们提出了一种技术，以放大我们的建设，允许有效地恢复恶意保证统计安全的安全属性。
英文摘要：
We address the problem of efficiently verifying a commitment in a two-party computation. This addresses the scenario where a party P1 commits to a value $x$ to be used in a subsequent secure computation with another party P2 that wants to receive assurance that P1 did not cheat, i.e. that $x$ was indeed the value inputted into the secure computation. Our constructions operate in the publicly verifiable covert (PVC) security model, which is a relaxation of the malicious model of MPC appropriate in settings where P1 faces a reputational harm if caught cheating. We introduce the notion of PVC commitment scheme and indexed hash functions to build commitments schemes tailored to the PVC framework, and propose constructions for both arithmetic and Boolean circuits that result in very efficient circuits. From a practical standpoint, our constructions for Boolean circuits are $60\times$ faster to evaluate securely, and use $36\times$ less communication than baseline methods based on hashing. Moreover, we show that our constructions are tight in terms of required non-linear operations, by proving lower bounds on the nonlinear gate count of commitment verification circuits. Finally, we present a technique to amplify the security properties our constructions that allows to efficiently recover malicious guarantees with statistical security.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
