The Advance of Ring Confidential Transactions

Abstract

Ring Confidential Transactions (RingCT) is a protocol associated with the privacy-focused cryptocurrency Monero and is used to hide the transaction amount from the third party while still providing the confidentiality of the hide transaction. With the Pederson commitment scheme, ring signature, and other cryptographic constructions, RingCT plays a major role in making the transactions of Monero private. As a privacy coin, Monero has the unique property of fungibility in the cryptocurrency market from the protocols implemented. These protocols provided opportunities and challenges for its future. In this paper, the version of the protocol implemented in Monero is first inspected, including the commitment to zero and the range proof. Then, two critical cryptographic constructions used by RingCT 2.0, the accumulator and the signature of knowledge, are introduced. Finally, the influence of RingCT and other privacy features and the current situation of privacy coin is discussed.