Etthereum 2.0

 I like proof of stake. Trusted miners would be sandbox trusted miners, automated escrow offices.

But provability is the best. Keep the contracts simple connected graphs, no loops, one node is a stable spot confirmed by trusted miners. Provable to the level of spectre, easy to do if the contracts come in short trusted miner agreements. 60% of different crupto ledgers could be handled by two step trusted miners, managed by hand held personal accounting bots.   It is sandbox standard.  Model all contracts as multiples of the mother contract, no double spending.

In this system, ledgers are asynchronous, ledger swaps possible, everywhere, and scofflaws ultimately caught.  Everyone gets to keep their current ledger system, each systems adapted to the user via a secure, hand held account manager. For a few hundred bucks and a live thumbprint we open the whole kit and caboodle. Keep ethereum  2.0 and 1.;0, all forms of bitcoin, swift, and quick load and dispense purchasing contracts.  At the heart of this is competition from the ARM designers, give us privileged access to hidden key, and keep some keys for the kernel only. They do their part for spectre, sandbox derives contract rules from that, and instruction cache swaps, shard boundaries, and miner agreements all bound the state.

But, it is obvious to all techies, this is perfectly reasonable. But it needs security at the fab.  Using the protected calls, the authenticity of a card ultimately determined. These chips will all have expiration times, they must be replaced and smart card reverified.  Standard practice today, in fact, the standard credit cared function is almost a built in to these chips.  The store equipment is a card, just like it, for about $150.

It is the trusted miners. They run on servers, they watch for reversals\, and can recall in respond. They take a percentage, they guarantee any provable contract, which are almost always ledger swaps or making change to pure cash (cash not currently on account).   The basic form allows the card to handle bond accounts, stock accounts, as well as the standard S/L accounts.  In each case the thumbprint rules an causes deposits, loans, swaps, and withdrawal; however the given ledger system wants is.  All of them provable contracts interspersed with trusted miner. All on timeout, there is no ledger in the card except that the owner keeps it, the card at its optimum, it a martingale on transactions.  The card will take the currently observable gradient that maximizes delivery.