TERCT: A Traceable and Editable Ring Confidential Transaction for Blockchain

Anonymous cryptocurrency, as a distributed application utilizing blockchain technology, aims to enhance the level of anonymity in user transactions, but it may also be used for illegal activities. Existing anonymous transaction protocols lack effective public verification of transaction traceability, which means that malicious users have the ability to avoid being tracked by creating counterfeit incomplete evidence. In addition, there is a conflict between the immutability of blockchain and privacy regulations such as General Data Protection Regulation (GDPR), and revision of on-chain data is urgently needed. In order to solve above issues, we propose a trackable and editable anonymous transaction protocol TERCT, which is used to trace the addresses and transaction amounts of participants in anonymous transactions and enable editability of transaction content. Compared with previous work, TERCT enables the editability of transaction content while maintaining anonymity and publicly verifiable traceability of transactions. This ensures that users not only can edit usergenerated transaction content but also cannot fabricate pertinent evidence to evade tracing. We prove the proposed TERCT protocol satisfies unforgeability, balance, anonymity and traceability. We compare its effectiveness with the original RingCT protocol, Wolverine scheme and Trct scheme by experiments. The results show that TERCT has less additional computational overhead.