Vitalik Buterin Advocates for ZK-Proofs to Audit X's Algorithm and Rankings

In a recent post on social media, Ethereum co-founder Vitalik Buterin is urging platforms like X to utilize cryptography and blockchain technologies, aiming to enhance the transparency and verifiability of their content-ranking systems.

Key Takeaways

Vitalik Buterin calls for X to implement zero-knowledge proofs (ZK-proofs) and blockchain for algorithm transparency.
He suggests that ZK-proofs could verify the fairness of content reach decisions while preventing censorship.
Concerns about social media leadership decisions highlight the need for a more accountable system.
The Digital Services Act by the European Union aims to enhance algorithm transparency and mitigate negative societal impacts from social media.

Vitalik Buterin pitches ZK-proofs to audit X algorithm and rankings

Buterin's Proposition for Transparency

In a post on Monday, Buterin argued that X should adopt zero-knowledge proofs (ZK-proofs) and blockchain technology to demonstrate the fairness of its content-reaching algorithm. He expressed concern over how X is currently run, particularly under Elon Musk's ownership, which he believes has negative implications.

Davide Crapis, the AI lead at the Ethereum Foundation, responded by emphasizing that if X purports to be a platform for free speech, it should disclose its algorithm optimization targets. He articulated that users need to understand the system and have the ability to make changes.

Buterin proposed a verifiable system that would use ZK-proofs for algorithmic decisions while also logging all content, likes, and retweets on a blockchain to prevent any potential censorship or misrepresentation of timestamps. He recommended that the full algorithm code be published with a delay of one to two years.

Image of ZK-Proofs
Source: Vitalik Buterin

ZK-proofs are a type of cryptography that verifies the truth of a statement without disclosing the underlying data. For example, they can confirm an individual's age without revealing their full identity. Although Buterin did not specify what aspects would be proven with ZK-proofs in his suggestion, it's likely they would show that algorithmic decisions adhered to particular guidelines without compromising sensitive information.

Related: Sunlight is more effective than censorship

Cryptographic Perspectives on Social Media

Buterin's thoughts align with the principles of decentralized social media platforms, often referred to as SocialFi. Although none of these initiatives have gained mainstream traction, they are increasingly being acknowledged by traditional, centralized counterparts.

In early 2025, Meta, the company behind Facebook and Instagram, blocked links to a decentralized Instagram alternative known as Pixelfed, labeling all links to this platform as “spam.” Other platforms, like Mastodon, reportedly faced similar restrictions.

The crypto community, known for its skepticism towards centralized authority, has expressed concerns about the implications of actions taken by leadership within social media platforms. Following Musk's announcement in January about prioritizing the promotion of educational content, many raised doubts about who would determine what qualifies as "informative" and whether this policy could suppress dissenting views. Musk faced accusations of restricting access to premium features for users holding opposing opinions.

At that time, Buterin encouraged Musk to uphold the principles of free speech on the platform, urging him not to ban users for dissenting opinions or expressions.

Related: Buterin says X’s new location feature ‘risky’ as crypto users flag privacy concerns

The Role of Social Media in Society

Research indicates that social media wields significant influence over societal norms and democratic processes. A 2024 study highlighted that “access to Facebook may increase belief in misinformation.”

Recent court filings suggested that Meta halted internal research regarding the mental health effects of its platform after discovering evidence indicating that its products could harm users. The findings indicated that participants who refrained from using Facebook for a week experienced reduced feelings of depression, anxiety, loneliness, and social comparison.

To address these challenges, the European Union has introduced the Digital Services Act, mandating transparency concerning the primary algorithm parameters and requiring platforms to assess and disclose the risks associated with their operations. These risks include potential adverse effects on civic discourse, elections, and public safety.

Furthermore, the Digital Services Act stipulates that vetted researchers must be granted access to platform data for independent systemic risk assessment. X's failure to comply with this requirement was recently cited by the European Commission as part of the justification for a €120 million (approximately $141 million) fine imposed earlier this month. Other factors include a lack of transparency concerning X's advertisement repository and the confusing nature of the blue verification checkmark that has led users to believe that verification was granted without meaningful checks on account ownership.