Paper 2021/520
Optimal Randomized Partial Checking for Decryption Mix Nets
Thomas Haines and Johannes Mueller
Abstract
One of the most important verifiability techniques for mix nets is randomized partial checking (RPC). This method is employed in a number of prominent secure e-voting systems, including Pret a Voter, Civitas, and Scantegrity II, some of which have also been used for real political elections including in Australia. Unfortunately, it turned out that there exists a significant gap between the intended and the actual verifiability tolerance of the original RPC protocol. This mismatch affects exactly the "Achilles heel" of RPC, namely those application scenarios where manipulating a few messages can swap the final result (e.g., in close runoff elections). In this work, we propose the first RPC protocol which closes the aforementioned gap for decryption mix nets. We prove that our new RPC protocol achieves an optimal verifiability level, without introducing any disadvantages. Current implementations of RPC for decryption mix nets, in particular for real-world secure e-voting, should adopt our changes to improve their security.
Metadata
- Available format(s)
-
PDF
- Category
- Cryptographic protocols
- Publication info
- Published elsewhere. 26th Australasian Conference on Information Security and Privacy
- Keywords
- Mixnets Verifiability E-voting RPC
- Contact author(s)
- thomas haines @ ntnu no
- History
- 2021-04-23: received
- Short URL
- https://ia.cr/2021/520
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2021/520,
author = {Thomas Haines and Johannes Mueller},
title = {Optimal Randomized Partial Checking for Decryption Mix Nets},
howpublished = {Cryptology {ePrint} Archive, Paper 2021/520},
year = {2021},
url = {https://eprint.iacr.org/2021/520}
}
