Abstract: In recent years, blockchain technology has been continuously developed, but with the development, problems have also emerged. For example, the problem of privacy data leakage on the chain and the problem of crosschain interaction of private data. In response to the above problems, a crosschain privacy sharing model based on an improved notary mechanism is proposed. First, the model designs a crosschain data sharing mechanism based on threshold proxy reencryption. This mechanism stipulates that notary nodes need to pledge a certain amount of tokens, crosschain initiators need to provide a certain amount of crosschain rewards, and honest notary nodes obtain tokens. Coin reward, the malicious notary node deducts a certain amount of deposit and gives it to the initiator. This mechanism effectively reduces the possibility that the notary node is a malicious node. Then, design a token locking mechanism based on hash locks and Merkle trees to ensure that cross chain initiators and notary nodes can achieve data trustworthiness across chains without mutual trust finally, experimental results and theoretical research prove that the proposed model has a low probability of malicious attack on the notary node and a high cost of malicious attack, and the algorithm used is better than other comparison schemes in terms of encryption and decryption efficiency.

Key words: blockchain, Merkle tree, smart contract, hash lock, notary mechanism

摘要： 近年来，随着区块链技术的不断发展，安全问题也随之出现.例如，链上隐私数据泄露和隐私数据跨链交互等.针对上述问题，提出一种基于改进公证人机制的跨链隐私共享模型.首先，设计一种基于门限代理重加密的跨链数据共享机制，该机制规定公证人节点需要质押一定量代币，跨链发起者需要提供一定量的跨链奖励，诚实公证人节点获取代币奖励，恶意公证人节点扣除一定量质押金给与发起者.该机制有效降低公证人节点为恶意节点的可能性；然后，设计一种基于哈希锁和默克尔树的代币锁定机制，确保跨链发起者和公证人节点在互不信任的前提下实现数据可信跨链；最后，实验结果和理论研究证明，所提模型公证人节点恶意攻击概率低、恶意攻击成本高，且所用算法在加解密效率方面优于其他比较方案.

关键词: 区块链, 默克尔树, 智能合约, 哈希锁, 公证人机制, 跨链交互