The part that's technically impossible is _keeping that key secure_. https://www.pcmag.com/news/master-key-for-tsa-approved-locks-leaked-again https://www.pcma

The part that's technically impossible is _keeping that key secure_. https://www.pcmag.com/news/master-key-for-tsa-approved-locks-leaked-again https://www.pcmag.com/news/master-key-for-tsa-approved-locks... More importantly, the thing that's technically impossible is a scheme to detect that the key has become compromised before it is used maliciously.