Timechain on Nostr: Cashu is an implementation of E-Cash, or Chaumian E-Cash, named after David Chaum, ...

Cashu is an implementation of E-Cash, or Chaumian E-Cash, named after David Chaum, because, in the 80's he invented it and made it into a company in the 90s. Of course his company used US $ as the base, instead of Bitcoin, but it's a way of issuing 'tokens' or 'note' which are long strings of numbers, issued by a mint, In exchange for, in this case, bitcoin. The string of numbers exists not in a blockchain on the web, but ON your phone when you possess a cashu note. The mint doesn't know who you are, but they are sure that they issued it, and how much the note is worth. So, if someone gives you a note, the first thing you do is make sure it hasn't been used before by checking with the mint, if not, you give it to them, and get a new one. This way, you don't have a note anyone knows you have. You can pass it to someone else or you can give it to the mint, who will give you sats. The mint knows nothing about you. You got your sats, but the mint doesn't know who you got it from.