A network program is a Secret Program the whole network depends on, so chain votes approve how it runs. Secret Money is a network program.
A chain vote names the software Secret Money runs and which validators' machines may run it.
One of those machines at a time holds the right to write Secret Money's records. The others stay ready to take over.
Secret Money regularly records a checkpoint of its state on the chain, and the chain accepts it only from the machine currently writing.
No other program can move Secret Money's coins, hold its funds, or read its records.
flowchart TD Vote[Chain vote] -->|names the software and machines| Machines[Approved validator machines] Machines --> Writer[Machine currently writing] Machines --> Standby[Machines ready to take over] Writer -->|checkpoint| Chain[Public chain]