Efficient verifiably encrypted ECDSA schemes from Castagnos-Laguillaumie and Joye-Libert encryptions
Publication Type
Journal Article
Publication Date
3-2024
Abstract
A Verifiably Encrypted Signature (VES) scheme encrypts a digital signature in a way that allows the public to verify the validity of the encrypted signature. Recently, several practical VES schemes for ECDSA have been proposed to enable escrowed transactions with cryptocurrencies. However, these schemes are inefficient in terms of both communication and computation, or require a large lookup table. In this paper, we present two efficient VES schemes for ECDSA that improve upon previous work. The first scheme is based on Castagnos-Laguillaumie (CL) encryption, while the second is based on modified Joye-Libert (JL) encryption. Our benchmark shows that our schemes outperform existing constructions by a factor of at least 2 in both computation and communication. Additionally, our solution does not rely on any lookup table. We demonstrate that these schemes can also be generalized to design VES for Schnorr signature scheme and EdDSA. The main technical contribution of this paper, which is of independent interest, is a zero-knowledge proof for the equality of the discrete log of an elliptic-curve point and that of a JL ciphertext. Importantly, the security of our proof does not rely on any non-standard assumptions.
Keywords
Cryptography, Standards, Protocols, Bandwidth, Symbols, Public key, Contracts
Discipline
Information Security
Research Areas
Cybersecurity
Areas of Excellence
Digital transformation
Publication
IEEE Transactions on Information Forensics and Security
Volume
19
First Page
4161
Last Page
4173
ISSN
1556-6013
Identifier
10.1109/tifs.2024.3375622
Publisher
Institute of Electrical and Electronics Engineers
Citation
YANG, Xiao; ZHANG, Chengru; XUE, Haiyang; and AU, Ho Man.
Efficient verifiably encrypted ECDSA schemes from Castagnos-Laguillaumie and Joye-Libert encryptions. (2024). IEEE Transactions on Information Forensics and Security. 19, 4161-4173.
Available at: https://ink.library.smu.edu.sg/sis_research/9209
Copyright Owner and License
Authors
Additional URL
https://doi.org/10.1109/tifs.2024.3375622