> Invalid signature probably will result from chip degradation or other electronic failures I'd consider that pretty unlikely. Degraded chips would most likely

> Invalid signature probably will result from chip degradation or other electronic failures I'd consider that pretty unlikely. Degraded chips would most likely provide no signature, not an invalid one. (Being able to randomly flip bits would be a big security problem for these kinds of ICs, so I'd assume they'd have robust protections against that.)