Abstract. We present the cryptographic implementation of "DEMOS", a new e-voting system that is end-to-end verifiable in the standard model, i.e., without any additional "setup" assumption or access to a random oracle (RO). Previously known end-to-end verifiable e-voting systems required such additional assumptions (specifically, either the existence of a "randomness beacon" or were only shown secure in the RO model). In order to analyze our scheme, we also provide a modeling of end-toend verifiability as well as privacy and receipt-freeness that encompasses previous definitions in the form of two concise attack games. Our scheme satisfies end-to-end verifiability information theoretically in the standard model and privacy/receipt-freeness under a computational assumption (subexponential Decisional Diffie Helman). In our construction, we utilize a number of techniques used for the first time in the context of e-voting schemes that include utilizing randomness from bitfixing sources, zero-knowledge proofs with imperfect verifier randomness and complexity leveraging.
DEMOS REF is an end-to-end verifiable e-voting system, which introduces the novel idea of extracting the challenge of the zero-knowledge proof protocols from the voters' random choices; we leverage this idea in our system too.
End-to-End Verifiable Elections in the Standard Model
EUROCRYPT
Computer Science