Specifications about #cashu

The notation, models and cryptography the rest of the specification is written in: blinding, signing, proofs, and how a token is serialised.

How a mint restricts its endpoints to users holding a token from an OpenID Connect service it trusts.

Keysets: how an id is derived from one, how a mint rotates them, and the input fee a wallet pays when spending ecash from one.

How a wallet fetches a mint's active public keys, one per amount, and what a keyset is.

The well-known secret format that turns a proof's secret into a spending condition the mint enforces.

Paying one Lightning invoice from several mints at once, all of them or none.

Response caching on the critical endpoints, so a wallet can safely replay a request that a network error interrupted.

How a wallet asks the mint to reissue blind signatures it once received, so a lost wallet can be restored.

How a wallet asks the mint whether a proof is unspent, pending, or already spent.

How to show a token too large for a static QR code as an animated one, using the UR protocol.

The swap operation, where a wallet hands proofs to the mint and receives new blind signatures in return.