UCoin: An Efficient Privacy Preserving Scheme for Cryptocurrencies

【Author】 Nosouhi, Mohammad Reza; Yu, Shui; Sood, Keshav; Grobler, Marthie; Jurdak, Raja; Dorri, Ali; Shen, Shigen

【Source】IEEE TRANSACTIONS ON DEPENDABLE AND SECURE COMPUTING

【影响因子】6.791

【Abstract】In cryptocurrencies, privacy of users is preserved using pseudonymity . However, it has been shown that pseudonymity does not result in anonymity if a user's transactions are linkable. This makes cryptocurrencies vulnerable to deanonymization attacks. The current solutions proposed in the literature suffer from at least one of the following issues: (1) requiring a trusted third-party entity, (2) poor performance, and (3) incompatible with the standard structure of cryptocurrencies. In this article, we propose Unlinkable Coin (UCoin), a secure mix-based approach to address these issues. In UCoin, the link between the input (payer) and output (payee) addresses in a transaction is broken. This is done by mixing the transactions of multiple users into a single aggregated transaction in which the output addresses have been secretly shuffled. In our protocol design, we first develop HDC-net, a secure shuffling protocol that enables a group of users to anonymously publish their data. Then, we deploy the proposed HDC-net protocol in the UCoin architecture (as a mixing unit) to generate the aggregate transactions. We show that UCoin (1) does not rely on a trusted third-party, (2) can mix 50 transactions in 6.3 seconds that is 18% faster than the current solutions, and (3) is fully compatible with the architecture of cryptocurrencies.

【Keywords】Bitcoin; Cryptography; Protocols; Privacy; Blockchains; Public key; Computer architecture; Anonymity; bitcoin; cryptocurrencies; privacy; unlinkability

【发表时间】2023 1-Jan

【收录时间】2023-03-21

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