Committed Vector Oblivious Linear Evaluation and Its Applications

发表信息

作者

笔记

We introduce the notion of committed vector oblivious linear evaluation (C-VOLE), which allows a party holding a pre-committed vector to generate VOLE correlations with multiple parties on the committed value. It is a unifying tool that can be found useful in zero-knowledge proofs (ZKPs) of committed values, actively secure multi-party computation, private set intersection (PSI), etc. To achieve the best efficiency, we design a tailored commitment scheme and matching C-VOLE protocols, both based on the learning parity with noise assumption. In particular, exploiting the structures of the carefully designed LPN-based commitment minimizes the cost of ensuring consistency between the committed vector and VOLE correlation. As a result, we achieve a 28× improvement over the protocol proposed in prior work (Usenix 2021) that uses ZKP to prove the correct opening of the commitment. We also apply C-VOLE to design a PSI protocol that allows one server to run PSI repeatedly with multiple clients while ensuring that the same set is used across all executions. Compared with the state-of-the-art PSI (CCS 2024) with similar security requirements, our protocol reduces the communication overhead by a factor of 35×.

我们提出了承诺向量不经意线性评估(Committed Vector Oblivious Linear Evaluation, C-VOLE)的概念,该技术允许持有预先承诺向量(committed vector)的一方与多方基于承诺值生成VOLE关联。它是一种通用工具,可应用于承诺值的零知识证明(Zero-Knowledge Proofs, ZKP)、主动安全的多方计算、隐私集合求交(Private Set Intersection, PSI)等场景。

为实现最优效率,我们设计了一种定制的承诺方案和与之匹配的C-VOLE协议,二者均基于噪声学习奇偶性假设(Learning Parity with Noise, LPN)。特别地,通过利用精心设计的基于LPN的承诺结构,我们最小化了确保承诺向量与VOLE关联间一致性的成本。实验结果表明,相较于先前工作(Usenix 2021)中使用ZKP证明承诺正确打开的方案,我们的协议实现了28倍的性能提升。

此外,我们将C-VOLE应用于PSI协议设计,使单一服务器能够与多个客户端重复执行PSI,同时确保所有执行中使用同一集合。与具备类似安全需求的现有最优PSI方案(CCS 2024)相比,我们的协议将通信开销降低了35倍。

关键词提炼

  1. 承诺向量不经意线性评估(C-VOLE)
  2. 噪声学习奇偶性假设(LPN)
  3. 隐私集合求交(PSI)
  4. 零知识证明(ZKP)
  5. 多方计算