Evosmt: A Novel Verifiable Privacy-Preserving E-Voting Protocol With A Sole Potentially Malicious Tallier

Electronic voting systems play an important role in modern democratic governance and smart city services supported by the Internet of Things (IoT). However, ensuring privacy and verifiability effectively remains a considerable challenge, especially for identifiable ballot (B-ID) schemes. To address this issue, this paper introduces Evosmt, a novel verifiable privacy-preserving e-voting scheme. As far as we know, this is the first scheme aiming to safeguard voters’ privacy in the presence of a potentially malicious tallier without trusting multiple authorities. Evosmt uses bit-XOR encryption to provide compact 0/1 ciphertext proofs and adopts an optimized authenticated garbled circuit (GC) with almost universal linear hash functions for efficient tallying and verification. A security analysis of the scheme has been conducted to demonstrate its correctness, privacy preservation, and verifiability. Through experimental evaluation and comparison with classic authenticated garbled circuit schemes, the proposed scheme has shown more than 100× improvement in terms of setup speed and communication efficiency of each voter when the number of voters exceeds 1000. Compared with classic e-voting schemes, the proposed scheme exhibits negligible encryption and proof cost and much faster verification due to the optimized authenticated garbled circuit method.Thanks to its lightweight and efficient design, the scheme is highly suitable for large-scale IoT-enabled e-voting applications in smart city governance and distributed democratic services.