Forge others' signatures alongside your own and let any reader prove that exactly one of the signatures is authentic, but not which one.
Fictional identities; illustrative keys and signatures.
Enter a message into the console; then sign with your Nostr nsec, your npub, and several others' npubs. Post the resulting signed message somewhere. Readers can then run the verifier to prove that exactly one of those npubs must be an authentic signature. Runs entirely in the browser.