The unprogrammed smart card

This card comes out of the box and supports on ledger system, the ability to send and verify encrypted digits to other smart cards.

No set of encrypted digits are sent twice.  This is no double spending.

There is no other requirement, but optonaly a smart card can randomly generate an encoded sequence of its own for heart beat purposes.

All differenciations of cash ledger systems for various currencies will pass through the smart card cash mechanism, and it is provable and spectre compliant.

Otherwise the smart card is biometric, handheld, and displays at least one account number and has two buttons, minimum. And it s counterfeit proof up to a stated cost of reverse engineering, and from this value the cash limit can be set. The smart card has magnetic stripe, and near field at a minimum, and can be a node on any other network architecture with an exposed address book (free entry and exit). Smart card vendors must declare their compatible list with other smart card vendors.  

Chip vendors are the weak point and must hold a secret master key unseen by humans, and kept under guard with very etc etc etc.   This is a necessity because chip vendors protect certain high security kernel operations on the instruction cache.

Program differentiation is simple, the ledger system will build a provable, segmented contract tree with the pure cash generic transmission as the top node.  Viewed in this mode, then, every contract is a path from a leaf through the root back to a leaf.  All contracts have a timeout. All exits from the finite directed graph are provable, and there are provably no loops. Any graph so constructed is spectre guaranteed by the smart card processor.

I expect the most common application is the minimal Swift bank node. In sandbox there is such a thing as a functional definition of currency ledger systems.  We consider liquidity on account to be actively trading in the pit and bearer cash to be idle and not on account, anonymous. 

Another is that currency ledgers define the legal methods for splitting accounts.  The generic smart card does no prevent fraudulent ledger applications, but all applications can be to be unprovable or not.  Provability is a well known accounting standard in automated contracts. The sandbox rule is tht valid contracts are povable.

Another accoubting standard is timeouts on contracts, at some time or count, contracts must be renewed. Noe, sandbox standards are meant to force mark to market,  cash is eventually put on account and trades.  Left overs, automatic unknowable, counterfeits all go to human contracts and criminal courts.

Think of  sandbox has having accounting standards, much like industry standards of data formats. The basic idea is that cash streams are martingale and the smart card is a balanced, bound commutator of accounts.  A portfolio manager, everyone gets one of these, easily worth 200 bucks a year.  Be sure to charge the tiny batteries.

Security at the chip vendor.

The same rule applies, is the cost of counterfeit very high? The master card, the secret key holder is in a fenced area. he independent security agency hired by outside accounting firm, the CEO and three board members must public bioprint into the fenced area.  

This entry be done at revision times, when they want updates on the key kernel ops.  These are big industry events and bring out the provability industry.  This system is already in operation, we have seen it in action with many revisions and with emergencies like spectre bug. Chip security at the vendor is the easy part. The chip vendors know they are guaranteeing as well as gold, they get bonuses.