Anonymity reduction attacks to Monero

© 2019, Springer Nature Switzerland AG. Monero is one of the most valuable cryptocurrencies in the market, focusing on users’ privacy. The built-in features in Monero help users to obfuscate the information of the senders and the receivers, hence achieve a better privacy compared to other cryptocurrencies such as Bitcoin. Previous studies discovered multiple problems within Monero systems, and based on these findings, Monero system has been improved. Although improvements have been made, we discovered that new attacks targeting the anonymity reduction can still be conducted in Monero system. In this paper we propose two attacks. The first is an extension of a known attack called Monero Ring Attack. The second one exploits Payment ID to discover the real output of a mixin. We then propose countermeasures to these attacks.