Pluralistic: 05 Dec 2020 – Pluralistic: Daily links from Cory Doctorow
Here’s what Thompson did: he hid a program in his compiler that would check to see whether you were compiling an operating system or a compiler. If you were compiling an OS, it hid a secret login for him inside of it.
If you were compiling a compiler, it hid the program that looked for compilers or operating systems inside of it.
Think about what this means: every OS you compiled had an intentional security defect that the OS itself couldn’t detect.
Great overview of computer security and trusted computing.