The Independent recently published an interview with Craig Federighi, talking about privacy and Apple chips.
Those chips are here to see whether they can withstand whatever assault anyone might try on them when they make their way out into the world. If they succeed here, then they should succeed anywhere; that’s important, because if they fail out in the world then so would Apple. These chips are the great line of defence in a battle that Apple never stops fighting as it tries to keep users’ data private.
I don’t think the article was written well, but to me the most interesting part was Secure Enclave stress testing, which involves temperature. I assume Apple is trying to prevent hacks like this.