[Vitalik: Signal is Exploring Registration Without Phone Numbers, True Privacy Requires 'Unlinkable Messages'] Foresight News reports that Ethereum co-founder Vitalik Buterin stated in a post that Signal recently announced it is exploring allowing users to register accounts without a phone number. He welcomed this move, believing it could help reduce reliance on the highly monopolized phone number system, lower identity security risks caused by SIM card swaps, and make it harder for governments to pressure Signal to block users in their countries based on nationality. Vitalik also pointed out that while this measure offers better privacy protection compared to the current situation, it only achieves 'confidentiality' and has not yet reached true anonymity. Metadata such as message sending time, frequency, and recipients could still be used to piece together identity associations. He argued that with the development of artificial intelligence, long-term persistent anonymous accounts are becoming outdated, and the only defensible form of privacy is 'unlinkable messages,' meaning that no one except the sender and receiver knows the identities of the communicating parties. This direction is currently being explored and advanced by new communication tools like Session and SimpleX, as well as coin-mixing network projects. Additionally, protection against spam and denial-of-service attacks will become the next key issues to address.