Secure Ranked Choice Online Voting System via Intel SGX and Blockchain

Abstract

Establishing trust in the election outcome is a very important problem. In order to solve it, we propose a practical ranked choice online voting system where every user can verify the validity of the outcomes. The proposed system combines the use of public blockchain and Intel Software Guard Extensions (SGX) to ensure that all standard requirements for voting systems are met, and at the same time to provide protection against malicious adversaries with administrative access. Each cast vote is submitted to the Intel SGX via a secure communication channel. The SGX verifies the eligibility and validity of the vote and encrypts it inside the SGX enclave. Later on, only the fingerprints (i.e., the hash values) of the encrypted votes are published on the public blockchain ledger before the deadline of the election. All encrypted votes are released after the deadline. Every voter can self-tally all submissions in encrypted form using the homomorphic property of our encryption system. The proposed protocol also achieves end-to-end voter verification. Our theoretical security analysis and experimental results show that the protocol is secure and is more efficient than previous alternative voting protocols.