[codethief]

> This is true, but the difficulty of making a general purpose FPGA fabric manipulate generic bitstream descriptions in an undetectable way is much harder than putting hidden backdoors in well defined ISAs.

Could you (or anyone else) elaborate on this? If possible, ELI5 please because I know very little about hardware. :)

[saagarjha]

I think a somewhat useful analogy would be the difference in difficulty of making a backdoored compiler versus a backdoored binary. The former has to deal with a lot more things than the latter if you'd like to effectively subvert it.