Messages in this thread | | | From | Ray Lee <> | Date | Mon, 23 May 2011 12:02:41 -0700 | Subject | Re: [BUG] perf: bogus correlation of kernel symbols |
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On Mon, May 23, 2011 at 3:49 AM, Ingo Molnar <mingo@elte.hu> wrote: > Well, since entropy does not get reduced on addition of independent variables > the right sequence is (pseudocode): > > rnd = entropy_cycles(); > rnd += entropy_rdrand(); > rnd += entropy_RTC(); > rnd += entropy_system();
I think you mean concatenation rather than addition? Or perhaps XOR, or a hash? It's pretty easy to show that the addition of n random variables evenly distributed between [0, 1] converges to 1/2 n +- 1/sqrt(n) (or numbers to that effect), which gives an attacker better chances than they would otherwise if they target the center of the distribution.
But none of this is to detract from your main point, which still holds. Structuring it such that other sources of randomness can be included as available keeps options open.
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