[Cryptography] new PRNG family

[Tom Mitchell]

On Fri, Dec 5, 2014 at 11:30 AM, Ray Dillinger <bear at sonic.net> wrote:

>
>
> On 12/04/2014 11:30 PM, Andreas Briese wrote:
> > i would like to put in my words, would you please indicate, if i am on
> the right track:
> >
>
 ....

> This is a degenerate "generator" because we lose
>

Any generator needs to be very cautious with impossible
state and results.

Consider a RNG (true or pseudo) if an analysis discovers that
a set of results is never generated than this can become a
problem.

Consider a lottery where a consortium can identify a block of
picks that automated quick picks never generate.   By playing
in that space alone the odds of sharing a result are vastly reduced
and thus increasing the return on investment.

Same for key generation. If key generation fails to apply with
an even hand to all possibilities in key space then the key space
exploration
to crack open the data is reduced a little or a lot.   Agencies might
try and  use alternative generators to make their key space less
vulnerable than a common public keyspace.

Rounding has the potential of introducing inequities in the computation.

Theft and other abuses are possible.    Decades ago I was playing with
calculating PI with a RNG based on some log and floating point mumble
foo.   Code from the book compiled and ran... Then to make the exercise
visible I began to plot the hits inside and outside the unit circle.
The pixels that turned on filled the screen except for arks of omission.
These systematic omissions might be the locus of winning tickets
in an illegal game and the rest of the space could be "sold" with
no payout risk.     I was living in Reno and working with folk that at
one time did work to validate electronic games.   Interesting discussions
followed...

The problem of RNGs is difficult.
Consider how difficult it would be to demonstrate that all possible
outcomes are possible and that impossible outcomes are a do
not care.






-- 
  T o m    M i t c h e l l
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