Buterin Backs Signal No-Phone Number Feature, Warns on Privacy

The open-source instant messaging app Signal is working to allow users to register on its network without a phone number. Although it has not been officially confirmed, Signal noted that the ability to register for Signal without a phone number is a frequently requested feature on its platform.

Ethereum co-founder Vitalik Buterin highlighted the latest development as “very welcome news from Signal.”

The Benefits of Signal’s “No Phone Number” Feature

In his latest post on X, Buterin identified the key benefits of Signal enabling this feature in its messaging app. He said enabling the proposed feature will reduce dependence on phone numbers. According to him, aside from privacy benefits, doing so on a highly oligopolistic system of checkpoints is good in itself.

Buterin further stated that phone numbers are not a good “root” of identity for many people from an access-control perspective. He also stated that allowing phone-number-free accounts will make it harder for anyone to discriminate against people by location, making it more difficult for governments to pressure the firm into blocking citizens.

How to Achieve True Privacy

Having identified the benefits of implementing a no-phone-number-registration feature, Buterin stated that in practice, pseudonymity is a dead concept in 2026. According to him, there are too many channels by which we accidentally slowly leak data about who we are. He cited the timing of messages, the pattern of who we send messages to, frequency and size, and the proliferation of AI-based means as elements that betray the concept of pseudonymity.

Buterin concluded that the only defensive form of privacy is message-by-message unlinkability, stating that such a system makes it impossible for a third party to access the elements and details of a given communication. He further noted that mixnet messengers, such as Session and SimpleX Chat, are exploring more viable privacy options. However, the technologies underpinning their solutions are often tagged as spam and trigger DoS attack protection.

He said the industry needs ways for people to prove their non-spammer status while maintaining message-by-message unlinkability. Buterin appreciated Signal’s efforts to create accounts without phone numbers and expressed hope that the industry will continue pushing the frontier of data leakage minimization.

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