My question is about the basics of the topic "creating digital cash".
At the very beginning of that topic the amount of the banknote and a serial number are the requirements for generating a signature. This signature is placed to avoid pirate copies of the banknote. That implies that the bank can trace the banknote and their customers by the serial number.
To anonymize the tracing a method called blind signature is introduced. My question is about the coherence between the serial number and signature for that banknote.
How can the bank generate a signature for a banknote without noticing the serial number while keeping the coherence between the signature and the serial number?