Cryptology ePrint Archive: Report 2017/921

RingCT 2.0: A Compact Accumulator-Based (Linkable Ring Signature) Protocol for Blockchain Cryptocurrency Monero

Shi-Feng Sun and Man Ho Au and Joseph K. Liu and Tsz Hon Yuen and Dawu Gu

Abstract: In this work, we initially study the necessary properties and security requirements of Ring Confidential Transaction (RingCT) protocol deployed in the popular anonymous cryptocurrency Monero. Firstly, we formalize the syntax of RingCT protocol and present several formal security definitions according to its application in Monero. Based on our observations on the underlying (linkable) ring signature and commitment schemes, we then put forward a new efficient RingCT protocol (RingCT 2.0), which is built upon the well-known Pedersen commitment, accumulator with one-way domain and signature of knowledge (which altogether perform the functions of a linkable ring signature). Besides, we show that it satisfies the security requirements if the underlying building blocks are secure in the random oracle model. In comparison with the original RingCT protocol, our RingCT 2.0 protocol presents a significant space saving, namely, the transaction size is independent of the number of groups of input accounts included in the generalized ring while the original RingCT suffers a linear growth with the number of groups, which would allow each block to process more transactions.

Category / Keywords: Cryptographic Currency; Anonymity

Original Publication (with minor differences): Published in ESORICS 2017

Date: received 8 Sep 2017, last revised 21 Sep 2017

Contact author: shifeng sun at monash edu; csallen@comp polyu edu hk; joseph liu@monash edu; YUEN TSZ HON@huawei com; dwgu@sjtu edu cn

Available format(s): PDF | BibTeX Citation

Version: 20170924:223513 (All versions of this report)

Short URL: ia.cr/2017/921

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