I was recently reminded of this.

A couple decades ago, I wrote a short paper that described how the basic approaches of cryptography and computer security lead to an efficient and practical privilege escalation attack against master-keyed mechanical locks, which I published in IEEE Security and Privacy (a nerdy computing technical journal).

https://www.mattblaze.org/papers/mk.pdf

TL;dr: Master-keyed locks have fundamental, exploitable weaknesses.

But I wasn't ready for what happened next.

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