[cryptography] Question on Entropy Gathering

Jeffrey Walton noloader at gmail.com
Sun Mar 3 16:21:51 EST 2013


On Sun, Mar 3, 2013 at 4:15 PM, Sandy Harris <sandyinchina at gmail.com> wrote:
> On Sun, Mar 3, 2013 at 3:30 PM, Jeffrey Walton <noloader at gmail.com> wrote:
>
>> In Jesse Walker's slide on "Requirements for random number generators"
>> (https://crypto.stanford.edu/RealWorldCrypto/slides/jesse.pdf), Walker
>> provides a simple gatherer on slide 10:
>>
>> unsigned before, after, entropy;
>> before = read_TSC();
>> usleep(0);
>> after = read_TSC();
>> entropy = (after – before) & 0x0ff;
>> Repeat until sufficient entropy harvested
>
> One possibly relevant paper:
> McGuire, Okech & Schiesser, Analysis of inherent randomness of the Linux kernel,
> http://lwn.net/images/conf/rtlws11/random-hardware.pdf
>
> My attempt at a generator based on such ideas:
> ftp://ftp.cs.sjtu.edu.cn:990/sandy/maxwell/
Thanks sandy. I remember looking through the code some time ago.

Jeff



More information about the cryptography mailing list