Vitalik: Signal's registration without a phone number is a good thing, but true privacy requires achieving "unlinkability of individual messages"

According to Vitalik Buterin's post, Signal is developing a feature to register accounts without a phone number. He welcomed this and listed three key benefits: reducing reliance on the highly oligopolistic phone number system, lowering SIM card hijacking risks, and preventing governments from blocking domestic users via phone numbers. However, Vitalik also pointed out that one should not be overly optimistic about privacy. He believes that in 2026, "pseudonymity" (decoupling long-term persistent accounts from real identities) is actually a "dead concept"—behavioral patterns such as message timing, contact frequency, and message size, coupled with AI's powerful analytical capabilities, create too many channels for identity recognition, making it difficult to truly evade.