Paper 2021/558
Verifiable Decryption in the Head
Kristian Gjøsteen, Thomas Haines, Johannes Müller, Peter Rønne, and Tjerand Silde
Abstract
In this work we present a new approach to verifiable decryption which converts a 2-party passively secure distributed decryption protocol into a 1-party proof of correct decryption. To introduce our idea, we present a toy example for an ElGamal distributed decryption protocol that we also give a machine checked proof of, in addition to applying our method to lattices. This leads to an efficient and simple verifiable decryption scheme for lattice-based cryptography, especially for large sets of ciphertexts; it has small size and lightweight computations as we reduce the need of zero-knowledge proofs for each ciphertext. We believe the flexibility of the general technique is interesting and provides attractive trade-offs between complexity and security, in particular for the interactive variant with smaller soundness. Finally, the protocol requires only very simple operations, making it easy to correctly and securely implement in practice. We suggest concrete parameters for our protocol and give a proof of concept implementation, showing that it is highly practical.
Note: This is the full version of the paper accepted at ACISP 2022.
Metadata
- Available format(s)
-
PDF
- Category
- Cryptographic protocols
- Publication info
- Published elsewhere. Major revision. Australasian Conference on Information Security and Privacy 2022
- Keywords
- verifiable decryptiondistributed decryptionlattice-based cryptoMPC-in-the-Headzero-knowledge proofimplementation
- Contact author(s)
-
kristian gjosteen @ ntnu no
thomas haines @ ntnu no
johannes mueller @ uni lu
peter roenne @ uni lu
tjerand silde @ ntnu no - History
- 2022-05-22: revised
- 2021-05-03: received
- See all versions
- Short URL
- https://ia.cr/2021/558
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2021/558,
author = {Kristian Gjøsteen and Thomas Haines and Johannes Müller and Peter Rønne and Tjerand Silde},
title = {Verifiable Decryption in the Head},
howpublished = {Cryptology {ePrint} Archive, Paper 2021/558},
year = {2021},
url = {https://eprint.iacr.org/2021/558}
}
