key: 2018-ballot-secrecy-from-NM-CPA
type: article
title: Non-malleable encryption with proofs of plaintext knowledge and applications to voting
authors:
  - Ben Smyth
  - Yoshikazu Hanatani
year: 2019
doi: 10.1504/IJSN.2019.103150
month: 12
journal: International Journal of Security and Networks
volume: "14"
number: "4"
pages: 191--204
description: >-
  This article presents a construction for coupling malleable ciphertexts with proofs to derive
  non-malleable ciphertexts, with applications to ballot secrecy.
keywords: >-
  asymmetric encryption, ballot secrecy, chosen plaintext attacks, elections, election scheme,
  electronic voting, e-voting, Helios, homomorphic encryption, indistinguishability,
  non-malleability, privacy, secrecy, voting
abstract: >-
  Non-malleable asymmetric encryption schemes which prove plaintext knowledge are sufficient for
  secrecy in some domains. For example, ballot secrecy in voting. In these domains, some
  applications derive encryption schemes by coupling malleable ciphertexts with proofs of plaintext
  knowledge, without evidence that the sufficient condition (for secrecy) is satisfied nor an
  independent security proof (of secrecy). Consequently, it is unknown whether these applications
  satisfy desirable secrecy properties. In this article, we propose a generic construction for such
  a coupling and show that our construction produces non-malleable encryption schemes which prove
  plaintext knowledge. Furthermore, we show how our results can be used to prove ballot secrecy of
  voting systems. Accordingly, we facilitate the development of applications satisfying their
  security objectives.
links:
  - file: Smyth18-ballot-secrecy-from-NM-CPA.pdf
    text: Draft
    alt:
      url: https://eprint.iacr.org/2019/026/
      text: Cryptology ePrint Archive version