Verifying ElectionGuard - a theoretical and empirical analysis

Abstract

End-to-end-verifiable voting systems can only meet their goals if independent auditors are capable of verifying election outcomes as easily and efficiently as possible. ElectionGuard is a prominent effort in this direction, in which simplifying the verification process guides several design decisions, from the choice of cryptographic group to the building blocks for encryption and zero-knowledge proofs. In this paper, we present the development of optimized ElectionGuard verifiers in the Go programming language, targeting versions 1.1 and 2.0 of the specification, focused on analyzability and efficiency. Our verifiers are built on an architecture emphasizing efficiency that exploits parallelism to achieve a running time up to 10 times faster than related work. We also show that version 2.0 of the specification introduces several changes that improve the verification performance by an overall factor of 2, with the decryption process being around 24 times faster. We expect that our design can be used as a reference for future ElectionGuard verifiers.