ZKP voting promises to unlock secure democracies

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The 2024 US presidential election has highlighted the public’s growing interest in prediction markets and citizen journalism. However, while blockchain-powered offerings promise to empower citizens like never before, the most pressing issue affecting the future of our government remains voter privacy and security. Paper systems are costly and slow, and current electronic voting systems lack privacy, transparency and accessibility, undermining trust in democracy.

Enter zero-knowledge proof: a privacy-preserving encryption method that provides concise and unfalsifiable evidence that offers a transformative solution for national elections. ZKPs can revolutionize democratic processes by enabling verifiable, tamper-proof votes, ensuring voter privacy, election integrity, and transparency without relying on trusted authorities. ZKPs have the potential to unlock mathematically secure democracies.

Understanding where and how paper ballots went wrong

Despite technological advances in every function of our daily lives, the United States voting system still relies heavily on paper ballots. In fact, in August this year, it was predicted that 98 percent of the votes cast for presidential candidates in November would be on paper. While paper systems are generally viewed as secure, they inherently require trust and leave voter data vulnerable to breaches, misuse, and identity theft.

Additionally, traditional systems provide voters with little transparency or mechanism to verify the accuracy of their votes, fueling public skepticism and disinformation. For example, the 2020 US election saw widespread allegations, in part because voters lacked a reliable method to independently verify the results. As we have seen, insecure systems erode trust and perpetuate myths about election integrity.

How do traditional electronic voting methods present flawed systems?

Although electronic systems have been introduced to modernize elections and reduce costs, they still pose a significant risk to fair elections and introduce trade-offs between security and trust. This is because these systems rely on centralized intermediaries, making them vulnerable to tampering, extortion, and privacy breaches.

Early attempts to solve these problems, such as blockchain-based systems, introduce decentralization and self-computation. However, these blockchain-based systems often fall short in scalability and security of voters’ personal information. The lack of any true privacy inherent in current decentralized blockchain technology, unlike paper or traditional electronic systems, risks compromising voter privacy, revealing the voter’s identity and ballot choices.

What is needed is a technological system that can ensure voter integrity and privacy and prevent manipulation while reducing the data stored on-chain; This is something that allows for faster and more efficient vote processing without compromising security. This is where ZKP technology stands out. By solving the balance between transparency and privacy while maintaining scalability, ZKPs provide a foundation for secure, verifiable and efficient voting.

Meet ToM evidence: The next generation solution for voter integrity

ZKPs provide the solution needed to protect voter privacy and enable scalable voting processes. This is because ZKPs allow the voter to prove eligibility or vote validity without revealing their identity or voting preference, ensuring both privacy and integrity in the process. To do this, ZKPs rely on mathematical principles that enable claims such as vote validity in elections to be verified without revealing any personal data or sensitive details. Additionally, ZK’s off-chain calculations can solve scalability issues in blockchain-based e-voting systems. By reducing on-chain storage requirements, this system enables large-scale elections while maintaining transparency, privacy, and universal verifiability.

Here’s a more in-depth look at how ZKPs can build mathematically secure democracies and solve problems with current electronic voting systems:

1. Protection of voter privacy: ZKPs allow voters to verify the validity of their votes or other documents without revealing essential personal data or documents, thus protecting their privacy. This is possible thanks to three components of the ZKP algorithm: completeness, robustness and zero knowledge. Completeness works like this: a statement (X) is true and both the prover and the verifier follow the protocol correctly, the verifier must accept the proof as true. Evidence cannot be tampered with, ensuring reliability. Similarly, the robustness component means that if statement (X) is false, the verifier will not be persuaded by the evidence even if everyone follows the protocol correctly.

2. Enabling decentralized record keeping: In a ZKP system, a decentralized and transparent ledger (blockchain) records votes, ensuring accountability and security.

3. Ensuring transparency and integrity in voting: ZKPs provide a collusion-proof system that allows voters to verify that their votes have been accurately recorded in the tally without revealing their voting preferences, ensuring trust and integrity in the voting process.

4. Establishing mathematical security: ZKPs provide robust guarantees that verify that the voting protocol is secure.

Real-world applications of ZKPs in voting

ZKP-based voting is no longer theoretical. In October 2024, Georgia’s leading opposition party, the United National Movement, launched “Unified Space”, an identity application created by Rarimo, a protocol specializing in decentralized digital identities. This app uses blockchain and ZKPs to enable secure and anonymous voting, aiming to combat low voter turnout by rewarding participation and protecting voter identities.

Other projects such as zkPassport, Anon Aandhaar and OpenPassport demonstrate the potential to integrate ZKPs into authentication systems, proving attributed information such as nationality or age without revealing privacy information.

Current limitations of ZKP-based identification

While ZKPs offer breakthrough potential for secure voting systems, they still face challenges, especially in relying on passports for verification. Passport ownership is not universal; Only 50% of the US population has a valid passport, and in many developing countries the rates are much lower. Moreover, passports lack biometric verification, making them vulnerable to fraud through stolen or forged documents. Corrupt document-issuing officials could theoretically manipulate voting results by creating invalid documents that pass verification.

Another key challenge is the persistence of cryptographic signatures associated with canceled or replaced passports. Even if a document is no longer valid, its digital signature often remains available, creating the risk of misuse. Finally, many ZKP-based systems rely on a single point of verification (typically a passport) rather than collecting confirmations from multiple sources such as national identity systems, banking institutions, or mobile operators. This trust increases the likelihood of system malfunctions or manipulation.

One solution to these challenges is to expand authentication sources to include confirmations from diverse and trusted validators. Incorporating biometric verification into the passport verification process can significantly reduce the risks associated with stolen or borrowed documents. Additionally, the development of encryption standards that allow invalidation of obsolete signatures would address security vulnerabilities caused by canceled or modified documents.

ZKPs represent a paradigm shift in secure voting by addressing vulnerabilities in traditional and blockchain-based systems. By enabling mathematically secure, privacy-preserving elections, ZKPs have the potential to promote trust, transparency, and participation in democratic processes. As ZKP technology improves, it has the potential to unlock democracies that are not only secure but also more inclusive, equitable and participatory.

This article was co-authored by Andre Omietanski and Amal Ibraymi.

Andre Omietanski and Amal Ibraymi

Andre Omietanski is general counsel at Aztec Labs, which is developing privacy-first Layer-2 on Ethereum, which allows developers to build privacy-preserving applications while ensuring compliance. Andre spent more than a decade at White & Case in London, where he left as a consultant and gained extensive, global and diverse experience in complex traditional finance transactions. Before joining Aztec Labs, he was a crypto advisor to early-stage startups in the Ethereum, Cosmos and Polkadot ecosystems.

Amal Ibraymi is legal counsel for Aztec Labs, where she supports the company’s legal efforts to defend privacy-enhancing technologies and decentralized finance. Prior to joining Aztek, Amal was a privacy partner in Willkie Farr & Gallagher’s New York and Paris offices, where she advised on data protection, cryptography and global privacy compliance. Amal also previously worked as a Privacy Fellow at the Legal Affairs Office of the United Nations Secretariat in New York City, the International Chamber of Commerce International Arbitration Tribunal in Hong Kong, and the OECD headquarters in Paris. Amal is dually educated in the US and France and holds a JD from NYU School of Law and a JD/MA from Sciences Po Paris.