Abstract
Verifiability is a key requirement for electronic voting. However, the use of cryptographic techniques to achieve it usually requires specialist knowledge to understand; hence voters cannot easily assess the validity of such arguments themselves. To address this, solutions have been proposed using simple tables and checks, which require only simple verification steps with almost no cryptography.
This simplicity comes at a cost: numerous verification checks must be made on the tables to ensure their correctness, raising the question whether the success of all the small verification steps entails the overall goal of end-to-end verifiability while preserving vote secrecy. Do the final results reflect the voters' will? Moreover, do the verification steps leak information about the voters' choices?
In this paper, we provide mathematical foundations and an associated methodology for defining and proving verifiability and voter privacy for table-based election protocols. We apply them to three case studies: the Eperio protocol, Scantegrity, and Chaum's Random-Sample Election protocol. Our methodology helps us, in all three cases, identify previously unknown problems that allow an election authority to cheat and modify the election outcome. Furthermore, it helps us formulate and verify the corrected versions.
This simplicity comes at a cost: numerous verification checks must be made on the tables to ensure their correctness, raising the question whether the success of all the small verification steps entails the overall goal of end-to-end verifiability while preserving vote secrecy. Do the final results reflect the voters' will? Moreover, do the verification steps leak information about the voters' choices?
In this paper, we provide mathematical foundations and an associated methodology for defining and proving verifiability and voter privacy for table-based election protocols. We apply them to three case studies: the Eperio protocol, Scantegrity, and Chaum's Random-Sample Election protocol. Our methodology helps us, in all three cases, identify previously unknown problems that allow an election authority to cheat and modify the election outcome. Furthermore, it helps us formulate and verify the corrected versions.
Original language | English |
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Title of host publication | CCS '21: Proceedings of the 2021 ACM SIGSAC Conference on Computer and Communications Security |
Publisher | Association for Computing Machinery |
Pages | 2632–2652 |
Number of pages | 21 |
ISBN (Electronic) | 9781450384544 |
DOIs | |
Publication status | Published - 12 Nov 2021 |
Event | 28th ACM SIGSAC Conference on Computer and Communications Security 2021 - Virtual, Seoul, Korea, Democratic People's Republic of Duration: 15 Nov 2021 → 19 Nov 2021 |
Conference
Conference | 28th ACM SIGSAC Conference on Computer and Communications Security 2021 |
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Abbreviated title | ACM CCS 2021 |
Country/Territory | Korea, Democratic People's Republic of |
City | Seoul |
Period | 15/11/21 → 19/11/21 |
Keywords
- elections
- protocol verification
- verifiability
ASJC Scopus subject areas
- Software
- Computer Networks and Communications