TTShuffle：一种区块链中基于两层洗牌的隐私保护机制

区块链隐私保护技术中的去中心化混币机制CoinJoin和CoinShuffle,分别因为代理节点不可信和节点需要层层传递加密而存在安全或效率低的问题,因此提出了TTShuffle,一种两层的隐私保护机制。首先将所有混币节点分成不同的组,通过层层加密在组内进行第一层洗牌,保护组内交易的敏感数据;然后由每个组派一个节点作为本组的代表,进行第二层的组间洗牌,保护所有组的敏感数据得到最后完整的交易内容。通过安全和实验分析表明,TTShuffle中40个混币参与者混币时间低于10 s,相比CoinShuffle机制提高了混币的效率,减少了混币时间,也确保了混币过程的隐私安全。

Ttshuffle: privacy protection mechanism based on two-tier shuffling in blockchain

In the block chain privacy protection technology,the decentralized coin mixing mechanism,CoinJoin and CoinShuffle,has the problem of low security or efficiency because the agent node cannot be trusted and the node need to pass encryption layer by layer,respectively.Therefore,this paper proposed TTShuffle,a two-tier privacy protection mechanism.Firstly,it divided all mixed currency nodes into different groups,and shuffled the first layer in the group through layers of encryption to protect the sensitive data of intra-group transactions;Then,each group sent a node as the representative of the group,and carried out the second layer of inter-group shuffling to protect the sensitive data of all groups to obtain the final complete transaction content.Through security and experimental analysis,it shows that the mixing time of the 40 participants in TTShuffle is less than 10 s,which improves the mixing efficiency,reduces the mixing time and ensures the privacy security of the mixing process compared with the CoinShuffle mechanism.