Appropriate sources of entropy
Posted May 26, 2008 16:34 UTC (Mon) by
aegl (subscriber, #37581)
In reply to:
Appropriate sources of entropy by kleptog
Parent article:
Appropriate sources of entropy
"the time between different dubious sources"
Agree with most of what you've said here ... but I have to comment that Linux doesn't use the time delta between different interrupt sources. It keeps a per-IRQ history and computes delta-t based on the previous interrupt using the same IRQ (if multiple devices are sharing the same IRQ, then this will be a cross-device time, but generally people try to arrange that devices do not share IRQs).
I have no idea why Linux does this ... in some cases using deltas between different interrupt sources would provide some defense against an attacker who does have tight control over the packets on one or more interfaces.
(
Log in to post comments)