keychat on Nostr: Here’s ChatGPT o3’s take on the history of using public keys as user IDs. Since ...

Here’s ChatGPT o3’s take on the history of using public keys as user IDs.

Since the invention of public-key cryptography in the 1970s, several consumer-facing applications have used the user’s public key directly as their ID:
• PGP / GPG (1991) – Users share a short PGP fingerprint (a hash of their public key) as their email identity.
• Bitcoin addresses (2009) – A Base58-encoded hash of a public key acts as the account for sending/receiving funds.
• Bitmessage (2012) – The “BM-…” address is a Base58 public-key hash used for encrypted mail and broadcasts.
• Tox ID (2013) – The long Tox string embeds the full public key; add it to start an E2E-encrypted chat.
• Tor .onion v3 / Ricochet IM (2014) – A 56-character .onion address is derived from an Ed25519 public key and serves as the chat ID.
• Secure Scuttlebutt (2014) – Feed IDs look like @<base64-public-key>.ed25519; the key is the permanent identity.
• Ethereum-style addresses (2015) – 0x… hashes of public keys function as login/payment accounts across smart-contract chains.
• Nostr npub (2021) – An npub is a Bech32-encoded 32-byte public key; any client can verify signatures from it.