Ethereum co-founder Vitalik Buterin has publicly praised Signal's early efforts to let users create accounts without providing a phone number, calling the development "very welcome" in a post on X.

Buterin, a long-standing advocate for privacy-focused technologies, has consistently lent both financial support and public visibility to platforms committed to protecting user content and metadata. His latest remarks align with a broader privacy agenda he has pursued across both messaging applications and the Ethereum network.

Buterin's Track Record on Privacy

Privacy has been a recurring theme in Buterin's public writing and advocacy. In his April 2025 essay, "Why I support privacy," he argued that whoever holds information holds power, and that concentrated data collection must be resisted wherever it is technically feasible to do so — particularly in the digital realm.

In November 2025, Buterin donated 128 ETH each to Signal and SimpleX Chat, praising both platforms for advancing open account creation and stronger metadata protections. SimpleX Chat, unlike Signal, was designed from the ground up without user identifiers of any kind, making it one of the few messaging platforms that collects no persistent identity at registration. At the time of his donations, Buterin underscored the very challenge Signal is now addressing: achieving Sybil and denial-of-service resistance without relying on phone numbers as an identity anchor.

Signal's Phone Number Requirement and Planned Changes

Signal, operated by the nonprofit Signal Foundation, is widely used by journalists, activists, and security professionals who depend on end-to-end encryption. Its phone number requirement, however, has long been viewed as its most significant privacy limitation, since phone numbers are tied to real-world identities, verifiable through telecom records, and vulnerable to SIM-swapping attacks.

Currently, Signal requires every new user to submit a phone number at registration — a policy that privacy advocates, including Buterin, have identified as a structural weakness in the app's privacy model.

Recent updates from AboutSignal.com, an independent site that tracks developments related to the app, indicate that commits to Signal's server code now reference backend support for phone-number-free accounts. These commits cover registration security, account handling, and regional data management.

Notably, one commit suggests the two account types would remain separate. Users would not be able to add a phone number to a number-free account after the fact, nor strip a number from an existing account. For now, the option appears limited to new sign-ups only.

In a talk recorded in March, Signal CTO Ehren Kret explained that the primary obstacle to phone-number-free registration has been the need to deter bad actors from mass-creating accounts. The challenge is not unique to Signal; most major encrypted messaging platforms, including WhatsApp and Telegram, rely on phone numbers in part because they serve as a built-in rate limiter against automated account creation.

"We gotta figure out some way to induce a cost for signing up without a phone number," Kret said. He noted that such a cost may or may not be monetary, and expressed hope that Signal could ship some version of the feature later this year.

Parallel Privacy Efforts on Ethereum

Buterin has also been a driving force behind efforts to build privacy features directly into the Ethereum mainnet. His roadmap targets uncensorable private transactions, unlinkable account activity, and private blockchain reads — though none of these features have gone live yet.

The Ethereum roadmap seeks to prevent outside observers from linking a user's on-chain activity or wallet queries to their identity. Signal's move to eliminate the phone number requirement addresses a fundamentally similar problem from a different angle: removing the identifier that ties a digital account to a real person. Both efforts reflect a growing recognition across the privacy-technology landscape that meaningful privacy requires minimizing the identifiers collected at the point of account creation, not merely encrypting data after the fact.