Passwordless Nostr login

A feature that has had multiple requests is an alternative to email and password login. I can think of a few ways to do this, but the way I like best is to use HTTP Basic auth and instead of a username or email we use the public key, and instead of a password we use an ECDH-generated shared secret. This is enough to authenticate with this site and no other site. The site will also provide its public key for use via a meta tag, say, ``, and could be included in the page document for any site supporting passwordless Nostr login.

Also, if email-style communications is required, we could instead broadcast messages to relays using the user's public key. They could also be encrypted DMs.