[Cryptography] A better random number generator...

[dj at deadhat.com]

> On Sun, Feb 22, 2015 at 12:30 PM, Henry Baker <hbaker1 at pipeline.com>
> wrote:
>
>> At 04:47 PM 2/18/2015, Tom Mitchell wrote:
>> >A talk at Stanford:
>> >The video will be online later...
>> >
>> >Talk by:
>> >Melissa O'Neill
>>
>
>
>> ......
>> >Algorithmic random number generators are everywhere, used for all kinds
>> of tasks, from simulation to computational creativity.
>>
> ........
>
>>
>> Come on, people!  Only 68 views so far.
>>
>> This video should be _required watching_ before anyone is allowed to
>> even
>> use "random number" in a sentence, much less in computer code.
>>
>
>
>> https://www.youtube.com/watch?v=45Oet5qjlms
>>
>>
> Give the watch count a +1,   I watched it via the Stanford link not
> youtube.
> It is a very clever approach to generating random numbers.
> And of interest she makes it clear what RNG is behind the
> library call of many OSs.
>
> If anyone wants to know the answer to the "tell you after the cameras
> are shut off" question we could address that in another thread.
>

Be careful. LCGs and PCGs and algorithms like xorshift are not
cryptographically secure. The goal is to have good statistical properties
at a minimum algorithmic cost. You can see in the talk that speed is one
property they aim for. However for more speed, parallelizable crypto modes
are better because you can throw optimized instructions like AES-NI at
them, or arbitrary amounts of silicon. But for crypto, you need secure
entropy extraction, optionally followed by a secure PRNG.