Published in Journal of Economic Literature, 61 (1): 295–97. Available at the Journal of Economic Literature
A review of: Voting over a Distributed Ledger: An Interdisciplinary Perspective. By Amrita Dhillon, Grammateia Kotsialou, Peter McBurney, and Luke Riley. Foundations and Trends in Microeconomics, vol. 12, no. 3. Boston: Now, 2021.
Fraud is a stubborn problem in democratic elections, and the history of voting technology is a history of attempts to reduce it. Votes might be manipulated at the ballot box, while voting records are in transit to counting centers, at the counting centers themselves, and at the point of broadcasting the result of an election. As Jones (2006) shows, many political reformers of the nineteenth century were technologists who designed voting machines that they believed would not just make elections more efficient, but also reduce real and perceived threats to the legitimacy of election results.
In their monograph, Voting over a Distributed Ledger: An Interdisciplinary Perspective, Amrita Dhillon, Grammateia Kotsialou, Peter McBurney, and Luke Riley explore and propose a significant upgrade to the technical infrastructure of voting: electronic voting over the internet using blockchain technology. Blockchains, the distributed ledger technology that underpins cryptocurrencies such as bitcoin and ethereum, use a combination of cryptography and economic incentives to achieve consensus over the state of a shared ledger without the need for a central authority to maintain and enforce that consensus. Dhillon et al. set up the terms of their investigation as follows. There are many intuitively appealing characteristics of voting over the internet. Voters could vote from their home devices or on mobile phones, potentially enhancing voter turnout (particularly among those who, for disability or socioeconomic reasons, find it difficult to turn up to a ballot box). Fully electronic votes could be counted immediately and at far lower cost.
Yet, as the authors detail in chapter 2, online voting has a wide range of risks that can threaten the real or perceived legitimacy of an election’s results. Some of these are cybersecurity risks: the software on a voters’ device might be corrupted through malware that manipulates the vote as it is cast, or the infrastructure that communicates votes to a counting authority could be targeted by adversaries with a denial-of-service attack. A counting service could go offline, possibly causing confusion that would lead to claims about illegitimacy. A more severe potential problem is that the counting authority might itself be corrupt. It is often observed that algorithms can be a black box to all but their creators; the difficulty of auditing a counting system might allow fraud to pass undetected. These potential risks are why many jurisdictions still use paper ballots or machines that print paper receipts-each of which present an audit trail manual verification by election supervisors or the voters themselves.
In chapters 3 and 4 the authors provide a straightforward description first of distributed ledger technology as a general category of decentralized systems, and then of blockchains as a special case of decentralized ledger. They distinguish correctly between “permissionless” systems, such as Bitcoin, where any user can join and participate in the consensus mechanism, and “permissioned” systems that will typically have a closed (and known) set of validators.
Chapters 5 and 6 are the core of the monograph, where the authors describe a high-level design of a blockchain voting system. Voters would be given a unique identity and vote by submitting a transaction directly to a node on the network. The node would then propagate that vote across the network. A voter could verify, using their private keys, that their vote had been recorded correctly and was included in the total vote count. Distributing control of the voting system across multiple nodes would reduce the risk of corruption by a central authority as well as provide a path for external observers to validate the correctness of the final count. Vote secrecy and anonymity could be assured using frontier cryptographic techniques such as zero-knowledge proofs that would allow anyone to check if a vote is valid without revealing any information about the vote other than its validity.
Voting over a Distributed Ledger is an effective argument for the feasibility of blockchain voting, but it is surprisingly modest. Some short sections suggest a much more ambitious vision. As the authors note, the step change in efficiency and reliability offered by blockchains could allow for the adoption of alternative voting schemes. Better technologies for voting open up possibilities for innovation in democratic form. It is hard, for example, to imagine a quadratic voting scheme (Weyl 2017) being built on paper ballots alone. In work with colleagues (Allen, Berg, and Lane 2019), I have explored a form of blockchain-based “liquid democracy” where voters could delegate their voting power while at the same time reserving the ability to directly vote on more personally salient issues.
Indeed, we already can see some of the possibilities of democratic innovation in the way that blockchain-based communities have innovated on the voting systems they use for organizational governance. Delegative democracy where voters retain an option to override their delegate’s vote is a core part of the Cosmos SDK, one of the major classes of blockchain protocols. More sophisticated systems are widespread in decentralized autonomous organizations (DAOs). One compelling example is the time-weighted voting systems that grant DAO token holders additional voting power for having locked up their tokens for a period of time, used most famously by the Curve protocol. As these examples show, reducing fraud, lowering costs, and increasing the speed with which elections are counted are important goals, but blockchains offer something else that should excite social scientists: a vast new design space for building systems of collective decision-making.
REFERENCES
Allen, Darcy W. E., Chris Berg, and Aaron M. Lane. 2019. Cryptodemocracy: How Blockchain Can Radically Expand Democratic Choice. Lanham, MD: Lexington Books.
Jones, Douglas W. 2006. “Technologists as Political Reformers: Lessons from the Early History of Voting Machines.” Paper presented at the Society for the History of Technology Annual Meeting, Las Vegas, NV, October 13. https://homepage.divns.uiowa.edu/ jones/voting/SHOTpaper.pdf.
Weyl, E. Glen. 2017. “The Robustness of Quadratic Voting.” Public Choice 172 (1-2): 75-107.