On Fri, 29 Mar 1996, JEFF C FLYNN wrote:
Does anyone know of articles regarding the possibility of subverting processor chips? Is this a realistic threat? Is it possible to hack vhdl compilers to embed intentional security flaws in silicon? Known cases? Attempts? TIA, Jeff
I received several responses to this question. My favorite was as follows...
This is probably science fiction, particularly at the VHDL level. Maybe someone could make a crime of opportunity out of a microcode flaw, but there's a risk of it being found out during testing.
To do it right would require collusion of the design and test teams. They need to ensure the back door stays closed, isn't tickled by "normal" testing and only opens when really requested. So a lot of people are in on the secret even before it gets exploited for nefarious purposes.
And what nefarious purposes would pay for the risks and costs of this? If the secret got out, the design team, product line, and company would be dead in the marketplace and probably spend the rest of their lives responding to lawsuits. What could you use this for that is worth the risk?
Trying to do it to the compiler (like Thompson inserting a back door in login using the Unix C compiler) is, again, theoretically possible. But the only reason to hack the compiler would be to do the deed without involving the processor development team. Risky in terms of building a reliable back door and the risk of detection. It might not work and the changes might be detected. To do it right would probably involve as many technical people as the processor development itself. Even "high grade threats" have finite resources -- there aren't that many processor design gurus in the world to start with.
At best, this might make a good plot element for Tom Clancy.>
Rick. smith@sctc.com secure computing corporation
Still, I'm left feeling a little uneasy. My reasons for this are 1) Trusting the processor means trusting something I don't fully understand. 2) Processors these days are extremely complex. 3) On April 3rd, at Interop, Peter Neumann (in his keynote presentation) disclosed that a random number generator chip used in slot machines had been compromised. This lead to a huge bogus jackpot, and an investigation that revealed the scheme. It looks like I may have no other option than to give some processor some degree of trust. Which processor I should choose, and why that one? TIA, Jeff _/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/ Specializing in the Design and Implementation of SECURE NETWORKS JEFF FLYNN & ASSOCIATES NETWORK SECURITY CONSULTING 19 PERRYVILLE IRVINE, CALIF. 92720 JEFF FLYNN TELEPHONE (714)551-6398 PRINCIPAL _/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/