Ethereum co-founder @VitalikButerin has welcomed moves by @signalapp to support account registration without a phone number, while issuing a stark warning: persistent pseudonymity online is e
Ethereum co-founder @VitalikButerin has welcomed moves by @signalapp to support account registration without a phone number, while issuing a stark warning: persistent pseudonymity online is effectively dead.
Buterin's comments came in response to evidence that Signal is reworking its registration system to allow phone-number-free accounts. It appears Signal is laying the groundwork for server support for accounts without a phone number, with recent commits to the public Signal-Server repository on GitHub reworking registration security, account locking, and country statistics so that all of it keeps working when an account has no number on file. Signal's CTO has also echoed the direction of travel publicly.
The phone number requirement has been the standing privacy objection to Signal for years. Buterin reinforced that concern on two fronts. First, phone numbers are a persistent SIM-swap vulnerability, giving bad actors a ready route to hijack accounts. Second, accounts free of phone numbers would complicate future efforts to restrict users by country of origin, thereby reducing the ability of governments to pressure the service into blocking their own citizens.
Phone numbers currently add a small barrier to the signup process, making it more difficult for bad actors to create large numbers of accounts, and Signal is exploring solutions to replace that requirement with another barrier while continuing to protect users and maintain the stability of the service.
Despite welcoming the Signal development, Buterin was blunt about its limits. He argued that pseudonymity has become obsolete in 2026, pointing to numerous channels through which users unintentionally reveal information about themselves over time, including message timing and patterns of contact. AI systems can now stitch these data points together to link an account to a real identity, regardless of whether a phone number is attached.
In Buterin's framing, the only meaningful privacy protection that survives this environment is what he calls message-by-message unlinkability, where no single communication can be tied to the same actor as any other. He noted that Signal has long offered confidentiality through end-to-end encryption, and the removal of phone-number requirements would add a layer of pseudonymity, in which an adversary might initially see only an opaque identifier. But that layer, he argued, is not enough against modern AI-driven analysis.
The territory he considers genuinely defensible is now being explored by mixnet-based protocols and privacy-focused messengers such as Session and SimpleX, which are designed to break the metadata links that conventional apps leave intact. The comments fit a broader pattern of Buterin pressing for stronger privacy defaults across both messaging and the Ethereum ecosystem.
Sources:Crypto Times: Buterin: Pseudonymity Dead Despite Signal ChangeReclaim The Net: Signal Could Be Working on Accounts Without Phone NumbersAbout Signal: Signal is working on registration without a phone number
