Let me explain a bit more what I am thinking. I imagine that the central bank issues many many 1 cent digital notes. Each note is unique (much like cash) with a

Let me explain a bit more what I am thinking. I imagine that the central bank issues many many 1 cent digital notes. Each note is unique (much like cash) with a unique private+public key. In this system, whoever holds the private key for a note owns the note (similar to cash). Now, the central bank also issues to each citizen a device that holds all the notes they own. If I want to give you a cent, I transfer the private key to you (by holding our devices close - no internet needed). But in order for you to trust that I indeed deleted the private key off my device, I need some sort of confirmation. This confirmation comes from a security enclave (consisting of a processor and the memory that stores the private keys) within my device. It should be able to emit a cryptographic certificate signed by some bank issued key that confirms the transaction. The idea is that security enclave can't be hacked to extract either the bank issued key or the algorithms that the enclave performs.