On 30.10.2012 14:30, Natanael wrote: > Yeah, this looks like TPM with software protection instead of hardware > protection. > > Rootkits can screw it up.
I guess that is why the researchers suggested an on-GPU challenge-response protocol implementation which would not hand out the initial SRAM state directly to any software. > Den 30 okt 2012 14:27 skrev "Solar Designer" <so...@openwall.com>: > >> This is very curious, but ... >> >> On Tue, Oct 30, 2012 at 10:08:06AM +0100, Eugen Leitl wrote: >>> Cloning the actual SRAM state in a GPU is not possible, said Dr. Lange. >> "What >>> we've done so far in our research is reading out this SRAM state. We can >> of >>> course copy this readout. What we're aiming for is to put an >> authentication >>> system in place where the GPU never hands over the raw data. Instead the >> GPU >>> uses it in a challenge-response protocol, just like the secret key in a >>> signature system or zero-knowledge protocol. This does rely on the OS >> and/or >>> hypervisor shielding the card from bad requests, such as ???hand over >> all your >>> secrets,???" she said. >> >> ... since it relies on OS and/or hypervisor security anyway, about the >> same functionality and security (not a lot of it) can be achieved by >> keeping the secret in a disk file (protected with filesystem/OS >> permissions) and having the crypto implemented in an OS driver (or >> privileged program). Use of a GPU does not appear to provide much >> advantage on top of that. It can't be physically cloned, but if OS >> security fails, then the GPU's secrets can be cloned and the >> authentication protocol simulated in host software (on attacker's >> machine, without the GPU). >> >> Alexander >> _______________________________________________ >> cryptography mailing list >> cryptography@randombit.net >> http://lists.randombit.net/mailman/listinfo/cryptography >> > > > > _______________________________________________ > cryptography mailing list > cryptography@randombit.net > http://lists.randombit.net/mailman/listinfo/cryptography > _______________________________________________ cryptography mailing list cryptography@randombit.net http://lists.randombit.net/mailman/listinfo/cryptography
