True, my point is only that it's far from free and therefore has limited purpose... You gain highly reliable interception signalling at the cost of significantl

True, my point is only that it's far from free and therefore has limited purpose... You gain highly reliable interception signalling at the cost of significantly increasing the probability of interception. As you suggest, if your use case is so sensitive or critical that you can afford to send 10 laptops and only use the ones that arrive in tact then fair enough - however for the more common scenario of just being a privacy conscious individual who would like some degree of ability to determine tampering in transit - this is a non-starter. It's not unthinkable that a method exists with as much resilience without attracting unwanted attention.