Bearer Tokens for Bitcoin: A Look at Cashu
Cashu is a Chaumian ecash protocol built on Bitcoin and Lightning, it's a precise cryptographic protocol with a clean spec and growing reference implementations. This talk goes inside the machinery: the Blind Diffie-Hellman Key Exchange that makes mint-side unlinkability possible, how the NUT specifications translate that into a concrete mint/wallet API and why a string of characters can be money.