Messages in this thread | | | From | (Matthias Urlichs) | Subject | Re: x86 MSRs - example program | Date | 5 Mar 1997 15:27:46 +0100 |
| |
In linux.dev.kernel, article <m0w1e9H-000AA6C@cerebro>, mlehmann@hildesheim.sgh-net.de (Marc Lehmann) writes: > >> ON the other hand... security hole????? how???????? > >> > >Cryptography. If you know exactly how long a given algorithm takes for > >different inputs, you can sometimes infer clues about the secret key. > > gettimeofyday is always available, and in that scenario is just > as good as rdtsc. > gettimeofday isn't nearly as accurate. While that's not an absolute barrier, it raises the number of iterations required to get accurate data.
-- You are not permitted to kill a woman who has wronged you, but nothing forbids you to reflect that she is growing older every minute. You are avenged fourteen hundred and forty times a day. --Bierce -- Matthias Urlichs \ noris network GmbH / Xlink-POP Nürnberg Schleiermacherstraße 12 \ Linux+Internet / EMail: urlichs@noris.de 90491 Nürnberg (Germany) \ Consulting+Programming+Networking+etc'ing PGP: 1024/4F578875 1B 89 E2 1C 43 EA 80 44 15 D2 29 CF C6 C7 E0 DE Click <A HREF="http://info.noris.de/~smurf/finger">here</A>. 42
| |