[MichaelBosworth]

I would just point out zero-knowledge proofs. Magically enough, no, that's not a necessary feature of blockchains.

Zcash allows an independent observer to verify that a transaction was authorized and completed. It does this without revealing (a) who the recipient was (b) who the sender was or (c) how much Zcash was sent.

Extending this idea to broader use cases: https://aztec.network/

[throwawayb4fd72]

Anyone interested is encouraged to look for links between worldcoin and zcash. You might find something.