[lkml]   [2001]   [Oct]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH][RFC] Allow net devices to contribute to /dev/random

> > Here is my reasoning. I'd like to quote drivers/char/random.c:
> > * add_interrupt_randomness() uses the inter-interrupt timing as random
> > * inputs to the entropy pool. Note that not all interrupts are good
> > * sources of randomness! For example, the timer interrupts is not a
> > * good choice, because the periodicity of the interrupts is too
> > * regular, and hence predictable to an attacker. Disk interrupts are
> > * a better measure, since the timing of the disk interrupts are more
> > * unpredictable.
> > *
> > * All of these routines try to estimate how many bits of randomness a
> > * particular randomness source. They do this by keeping track of the
> > * first and second order deltas of the event timings.
> Obviously the timer interrupt would be the worst idea ever. Its the
> same value (HZ) on almost all versions of Linux (Alpha being on example
> where it is not the same).

Actually, not quite. On 2.4.9 system, console kept interrupts disabled
for so long that timer interrupt was pretty good source of randomness.

I'm "In my country we have almost anarchy and I don't care."
Panos Katsaloulis describing me w.r.t. patents at
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-03-22 13:03    [W:0.097 / U:1.872 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site