What you're describing isn't that much different than using cryptographic signatures. Give up control of the chip and let em write whatever they want to it, but

What you're describing isn't that much different than using cryptographic signatures. Give up control of the chip and let em write whatever they want to it, but only use the data if it was signed by some private key. This is better for libre too, because you can manage your own keys (presuming you can get root access to whatever low level controller reads and loads the flash).