Niel Liesmons on Nostr: brugeman 's enclave option is also cool btw. You can spin it up in the enclave and ...

brugeman (npub1xdt…ntxy) 's enclave option is also cool btw.

You can spin it up in the enclave and have code in there that can tell you if the key has already been seen or not. Including by the service provider.

No need for multiple service providers to come together in concert. Just, the user that shouldn't trust/use an "already seen" key.