CryptoDB
Lattice-based Zero-knowledge Proofs for Blockchain Confidential Transactions
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| Presentation: | Slides |
| Conference: | PKC 2025 |
| Abstract: | We propose new zero-knowledge proofs for efficient and postquantum ring confidential transaction (RingCT) protocols based on lattice assumptions in Blockchain systems. First, we introduce an inner-product based linear equation satisfiability approach for balance proofs with a wide range (e.g., 64-bit precision). Unlike existing balance proofs (MatRiCT and MatRiCT+) that require additional proofs for some ''corrector values'', our approach avoids the corrector values for better efficiency. Furthermore, we design a ring signature scheme to efficiently hide a user’s identity in large anonymity sets. Different from existing approaches that adopt a one-out-of-many proof (MatRiCT and MatRiCT+), we show that a linear sum proof suffices in ring signatures, which could avoid the costly binary proof part. We further use the idea of ''unbalanced'' relations to build a logarithmic-size ring signature scheme. Finally, we show how to adopt these techniques in RingCT protocols and implement a prototype to compare the performance with existing approaches. The results show our solutions can reduce up to 50% and 20% proof size, 30% and 20% proving time, 20% and 20% verification time of MatRiCT and MatRiCT+, respectively. We also believe our techniques are of independent interest for other applications and are applicable in a generic setting. |
BibTeX
@inproceedings{pkc-2025-35153,
title={Lattice-based Zero-knowledge Proofs for Blockchain Confidential Transactions},
publisher={Springer-Verlag},
author={Shang Gao and Tianyu Zheng and Yu Guo and Zhe Peng and Bin Xiao},
year=2025
}