Your suggestion to the commenter of PGP, then email doesn't really make sense given their reported use case. The cryptographic components of PGP which allow fo

Your suggestion to the commenter of PGP, then email doesn't really make sense given their reported use case. The cryptographic components of PGP which allow for signed messages in the email setting are the same components that would allow for signed messages on a blockchain. But a blockchain protocol can natively support key exchange, symmetric encryption and digital signatures; PGP only natively supports asymmetric encryption and digital signatures. Further, while email is originally a decentralized protocol, it does not mirror all messages from all email addresses to every other email address across every mail server on the internet. If you were to take PGP, bolt it onto a modified email protocol that requires all mail servers to hold copies of all mail, you'd end up with something substantially the same as a blockchain. You can question the commenter's purpose in wanting all of this, but according to their stated use case, a blockchain actually sounds fairly reasonable from a technical perspective. Finally, the commenter said that performance concerns were not an issue. But for the sake of correction: they also mentioned Tendermint specifically Tendermint is capable of scaling to high thousands and low tens of thousands of transactions per second. I'm not sure why you keep talking about Bitcoin when the commenter specifically said they weren't using Bitcoin. That makes half of your comment not applicable to what they're talking about.