Buterin suggests using zero-knowledge proofs in social algorithms

Ethereum co-founder Vitalik Buterin has outlined a proposal that would utilize zero-knowledge (ZK) cryptography to enhance the transparency of social media algorithms, aiming to make their behavior verifiable without exposing sensitive data or proprietary code.

The idea arises from a debate over algorithmic amplification, coordinated online activity, and the responsibilities of platforms that portray themselves as defenders of free speech. 

The proposal is based on comments made by Ethereum Foundation AI lead Davide Crapis, who stated that platforms claiming to support free expression should provide details about their optimization goals for their algorithms. Buterin took this idea further by suggesting that any algorithmic decision, such as content ranking, recommendation, or weighting engagement, could be backed by a zero-knowledge proof.

Zero-knowledge proofs as a tool for algorithm accountability

Under Buterin’s proposal, platforms would produce cryptographic proofs that algorithmic results align with preset goals. He proposed that the creation time of content and the timestamp of engagement could be recorded using blockchain to minimize the risk of censorship, suppression, or retroactive manipulation of content. 

I would go further. ZK-prove every decision made by the algorithm (ideally have content and likes/RTss timestamped onchain so the server can't censor or lie about time), and commit to publishing the full algorithm code with a 1-2 year delay.

— vitalik.eth (@VitalikButerin) December 15, 2025

To alleviate concerns about intellectual property and system security, Buterin suggested that the full algorithm code should not be released immediately, but rather after a delay of one to two years.

The discussion gained attention following Buterin’s comments on what he referred to as coordinated attacks against Europe on social platforms in public. In follow-up exchanges, he warned that allowing a platform to become a symbol of free speech worldwide, yet opening it up to large-scale, coordinated harassment, could result in a long-term backlash against open discourse.

The larger debate also brought into focus concerns over automated amplification. Participants noted the potential for AI-driven bot networks to generate large volumes of synthetic engagement, suggesting that “more speech” is often insufficient to counter harmful narratives.

Combining ZK proofs with other cryptographic systems

In addition to social algorithms, Buterin has proposed placing zero-knowledge proofs on top of other cryptographic algorithms, such as multi-party computation (MPC), fully homomorphic encryption (FHE) and trusted execution environments (TEE).

Among such applications, he has singled out voting systems, where coercion and privacy resistance are paramount to the safety of participants in blockchain-based governance. To ensure the security of the people who make the decisions, blockchain communities have already studied the ZK-based voting models, and they are becoming more and more popular among people who are interested in privacy-sensitive systems. This layered architecture is expected to reduce the risks that would be experienced if the cryptographic tools were implemented in isolation. 

Adoption, technical progress, and ongoing risks

There has been a huge adoption of zero-knowledge technology. As of 2025, the total value locked in protocols built on ZK was more than $28 billion. ZK rollups have also been used by major institutions, like Goldman Sachs, Sony, and Deutsche Bank to secure transactions, verify NFTs, and compliance-related operations as well.

Over $ 100 billion worth of transactions using stablecoins is now being carried out on ZK rollups, with a huge portion represented by the stablecoins USDT and USDC.

Technically, the set of protocols written by Buterin, known as the GKR protocol codes, has made the verification of complex computations more efficient, allowing full nodes to be run by ordinary users using standard hardware.

If you're reading this, you’re already ahead. Stay there with our newsletter.