Re: Could this be applied to random(4)?

2016-05-29 Thread Stephan Mueller 
Am Freitag, 27. Mai 2016, 16:09:53 schrieb Sandy Harris:

Hi Sandy,

> On Fri, May 27, 2016 at 2:30 PM, Stephan Mueller  
wrote:
> > This document describes extractors. Those extractors are intended to
> > combine *independent* sources with weak entropy.
> > 
> > None of our sources we have in add_*_randomness are independent.
> 
> No, but it would be easy to get two independent sources, interrupts
> and some sort of timer jitter thing as in my maxwell, your jitter
> driver, havege, ...

I think I would concur with you here. From my LRNG code:

static int lrng_pdrbg_seed_internal(u8 *outbuf, u32 outbuflen, bool 
fullentropy,
bool drain)
{
...
/*
 * Concatenate the output of the noise sources. This would be the
 * spot to add an entropy extractor logic if desired.
...

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Ciao
Stephan
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Re: Could this be applied to random(4)?

2016-05-27 Thread Stephan Mueller 
Am Freitag, 27. Mai 2016, 13:38:05 schrieb Sandy Harris:

Hi Sandy,

> A theoretical paper on getting provably excellent randomness from two
> relatively weak input sources.
> https://www.sciencenews.org/article/new-technique-produces-real-randomness

This document describes extractors. Those extractors are intended to combine 
*independent* sources with weak entropy.

None of our sources we have in add_*_randomness are independent.

In addition, I am not sure why this research is so hyped. I think that the 3-
source extractor described in [1] is more efficient and easier to implement

[1] "Extracting Randomness Using Few Independent Sources" by Boaz Barak, 
Russell Impagliazzo, Avi Wigderson

Ciao
Stephan
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Could this be applied to random(4)?

2016-05-27 Thread Sandy Harris 
A theoretical paper on getting provably excellent randomness from two
relatively weak input sources.
https://www.sciencenews.org/article/new-technique-produces-real-randomness
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