AFIAK
Nostr uses bitcoin taproot keys and schnorr signatures
Slashtags use ed25519 private keys and a custom derivation of public key
DIDs ("web5", bluesky) use did methods to define identity (there's 100+), verifiable claims for signatures (ongoing work in progress)
Nostr benefits from being finished and easy to implement.
There are over 100 nostr projects on github alone. With more than one new project daily:
worse is better?
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