We broke the "encryption" (more like scrambling) of the AMD K8 and K10 CPU microcode updates. We released tooling to write and apply your own microcode updates. AMD did not take any actions against us. Granted, this was a university project so we clearly were within the academic context, but we were in no way affiliated with a too big to sue company.
> Granted, this was a university project so we clearly were within the academic context, but we were in no way affiliated with a too big to sue company.
Even without supposed goodwill of AMD and seeing things a different way being a) affiliated with a university b) outside the USA may have changed some of the equation.
I have not looked at the format of the microcode yet, so this is only based on the blog post and discussions. K8 and K10 were based on Risc86 just like Zen seems to be. There also are some parallels, especially when it comes to sequence words and branch delay slots. There are also major differences like moving from triads to quads. I assume there are quite some similarities, but the current authors are better qualified to answer this at this point.
Even without supposed goodwill of AMD and seeing things a different way being a) affiliated with a university b) outside the USA may have changed some of the equation.