Title
MatRiCT - Efficient, Scalable and Post-Quantum Blockchain Confidential Transactions Protocol.
Abstract
We introduce MatRiCT, an efficient RingCT protocol for blockchain confidential transactions, whose security is based on "post-quantum'' (module) lattice assumptions. The proof length of the protocol is around two orders of magnitude shorter than the existing post-quantum proposal, and scales efficiently to large anonymity sets, unlike the existing proposal. Further, we provide the first full implementation of a post-quantum RingCT, demonstrating the practicality of our scheme. In particular, a typical transaction can be generated in a fraction of a second and verified in about 23 ms on a standard PC. Moreover, we show how our scheme can be extended to provide auditability, where a user can select a particular authority from a set of authorities to reveal her identity. The user also has the ability to select no auditing and all these auditing options may co-exist in the same environment. The key ingredients, introduced in this work, of MatRiCT are 1) the shortest to date scalable ring signature from standard lattice assumptions with no Gaussian sampling required, 2) a novel balance zero-knowledge proof and 3) a novel extractable commitment scheme from (module) lattices. We believe these ingredients to be of independent interest for other privacy-preserving applications such as secure e-voting. Despite allowing 64-bit precision for transaction amounts, our new balance proof, and thus our protocol, does not require a range proof on a wide range (such as 32- or 64-bit ranges), which has been a major obstacle against efficient lattice-based solutions. Further, we provide new formal definitions for RingCT-like protocols, where the real-world blockchain setting is captured more closely. The definitions are applicable in a generic setting, and thus are believed to contribute to the development of future confidential transaction protocols in general (not only in the lattice setting).
Year
DOI
Venue
2019
10.1145/3319535.3354200
CCS
Keywords
Field
DocType
Lattice, Zero-Knowledge, RingCT, Post-Quantum, Ring Signature, Group Signature
Quantum,Confidentiality,Computer security,Computer science,Blockchain,Scalability
Conference
Volume
ISBN
Citations 
2019
978-1-4503-6747-9
1
PageRank 
References 
Authors
0.34
0
5
Name
Order
Citations
PageRank
Muhammed F. Esgin1124.99
Raymond K. Zhao241.13
Ron Steinfeld3237.99
Joseph K. Liu4113467.24
Dongxi Liu531240.40