Novel Blockchain-based Protocols for Electronic Voting and Auctions

The Hong Kong University of Science and Technology
Department of Computer Science and Engineering


MPhil Thesis Defence


Title: "Novel Blockchain-based Protocols for Electronic Voting and Auctions"

By

Mr. Zhaorun LIN


Abstract:

Programmable blockchain has long been a hot research topic given their 
tremendous use in decentralized applications. Smart contract, using 
blockchain as its underlying technology, inherits the desired properties 
such as verifiability, immutability, and transparency, which makes it a 
great suit in trustless environments.

In this thesis, we consider several decentralized protocols to be built on 
blockchains, specifically using smart contracts on Ethereum. We used 
algorithmic and cryptographic tools in our implementations to further 
improve the level of security and efficiency beyond the state-of-the-art 
works. We proposed a new approach called Blind Vote, which is an 
untraceable, secure, efficient, secrecy-preserving, and fully on-chain 
electronic voting protocol based on the well-known concept of Chaum's blind 
signatures. We illustrate that our approach achieves the same security 
guarantees as previous methods such as Tornado Vote, while consuming 
significantly less gas. Thus, we provide a cheaper and considerably more 
gas-efficient alternative for anonymous blockchain-based voting. On the 
other hand, we propose a new family of algorithms for private, trustless 
auctions that protect bidder identities and bid values while remaining 
practical for smart contract execution. We ensure trustlessness by running 
the auction logic in a smart contract, thereby eliminating reliance on any 
single trusted party. This approach prevents bid tampering, front-running, 
and collusion by enforcing immutability and decentralized verification of 
bids. The resulting protocol uniquely combines efficiency, trustlessness, 
and enduring bid privacy, offering a scalable and secure solution for 
blockchain-based marketplaces and other decentralized applications.


Date:                   Friday, 1 August 2025

Time:                   9:00am - 11:00am

Venue:                  Room 3494
                        Lifts 25/26

Chairman:               Prof. Siu-Wing CHENG

Committee Members:      Dr. Jiasi SHEN (Supervisor)
                        Dr. Amir GOHARSHADY (Co-supervisor, Oxford)
                        Prof. Raymond WONG