Making sub collections of smart card keys, merchant clubs

We had rules on keys, no human knows them, they cannot be sent or received, and key values are added to the cards with an in person biometric visit to the top secret node.  From these rules the security architecture is set.

Complete separate segments keys are possible, and available to use, under the same rules.  We can add keys as needed with a visit. My local merchant can have his public key erncribed in my card, and we can each have a matched pair of private keys.

 ATMs in this scenario remain, but they have an additional, more important function, they can do bio match.  So my card carrys my merchant's card ID, and request to a bio matched to his public key, and shared key.  The ATM can do that.

If my card gets stuffed with useless keys, I trade it in for 50 bucks. However, my card has enough intelligence to collect sets of keys and use them together for particular trades. And when he does this, the background security consistency checks are much faster, the merchants already has trust.  This can be done without revealing any other structure to the hackers, I think. If folks did this, however, after that fact counterfeit checking is very swift, misplaced patterns noticed and tracked, because, I think, card ID is available to the crypto cops.   In other words, a spatial match, lets the cops hone in on where a suspected human might be.

But it is still  pattern matching, still valid legally, and really helps with security.  Tracing serial number on paper cash was allowed, and tracing patterns of card ID is also.