[lkml]   [2008]   [May]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [PATCH] drivers/net: remove network drivers' last few uses of IRQF_SAMPLE_RANDOM
    > For systems with high resolution timers, even if an attacker has total
    > knowledge/control of the network, it doesn't seem realistically possible
    > for them to determine the low order bits of the nanosecond timer of
    > disk and network I/O system calls, if those were used as a source of
    > entropy.

    Around the same time I was working on getting the performance figures
    for the RNG in the Infineon TPM in the system I had, I tried, however
    briefly, to concoct a test using netperf and pulling the ITC on an
    Itanium processor to generate some randomness. I'm not at all sure I
    was doing things correctly - I was pulling the bottom one to 4 bits of
    the ITC after each call to recv() of a TCP_RR test - but when I tried to
    feed the resulting trickle of data through diehard (which I may have
    been running poorly) it was giving nothing but a p value of 0.000000
    which while I don't grok the p-value itself, I understand that
    consistent value of 0.000000 is bad :(

    So, I may have had a bad test case. If someone has some suggestions for
    a better test of the low-order-bits-of-the-interval-timer hypothesis
    I'd love to hear about them.

    rick jones

     \ /
      Last update: 2008-05-27 18:47    [W:0.028 / U:14.156 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site