MetaMask implements EIP-4361
MetaMask, a self-managed wallet for crypto assets (virtual currency), announced on the 24th that it implemented EIP-4361.
EIP-4361 (Sign In with Ethereum) is the ability to use wallet addresses to authenticate web services. Allows wallet addresses to be used as self-managed identities instead of centralized identities such as Gmail.
This is a move to strengthen security when connecting to dApps that implement EIP-4361 and to protect users from phishing attacks.