一种基于LWE‐CPABE的区块链数据共享方案

为应对量子计算对区块链上基于数论的隐私保护技术所带来的威胁，将区块链技术与格属性基加密算法有效融合，提出一种基于格的后量子CPABE区块链数据共享方案。将容错学习（LWE）作为方案的困难问题假设，构造一种基于格的密文策略属性基加密算法LWE-CPABE，抵御量子计算对公钥密码安全的攻击，实现数据的安全共享。设计算法参数的标准格式化交易结构，以满足LWE-CPABE算法的可追责性。在此基础上，给出交易生成与交易验证智能合约，以实现交易的自动验证与共识。功能性分析与仿真实验结果表明，该方案在算法初始化、加解密以及密钥生成的计算效率方面均优于传统的基于双线性映射理论的CPABE方案，可实现区块链上数据的高效、安全、动态共享与隐私保护，明显提高区块链数据共享安全性。

A Blockchain Data Sharing Scheme Based on LWE-CPABE

To solve the threat that quantum computing poses to the privacy protection technology using number theory applied to blockchains, a post-quantum Ciphertext-Policy Attribute-Based Encryption(CPABE) blockchain data sharing scheme based on lattice theory is proposed in this paper by effectively integrating blockchain technology and a lattice-based attribute-based encryption algorithm.First, using the Learning With Errors (LWE) problem, a lattice-based LWE-CPABE algorithm is constructed, which can effectively resist quantum computing attacks on public key cryptography to realize secure data sharing.Second, the standard formatted transaction structure of the algorithm parameters is designed to satisfy the accountability requirements associated with the LWE-CPABE algorithm.Finally, an intelligent contract for transaction generation and transaction verification is designed to realize the automatic verification and consensus of a transaction.Functional analysis and simulation results demonstrate that the initialized encryption as well as the key generation efficiency using the proposed algorithm is superior to the traditional CPABE scheme based on bilinear mapping theory.The proposed LWE-CPABE achieves higher efficiency and improves privacy protection in blockchain dynamic data sharing scenarios.