Re: Good enough for crypto?

"Ernst Lippe" <[EMAIL PROTECTED]> writes:
> The total entropy of any PRNG is equal to the amount of information
> in its parameters. 

Plus the information of specifying which PRNG is being used.

However, that's normally very little indeed. And yes, it's 
practically impossible to define exactly how much it is.
(Effectively I'm pushing the information content towards teh 
Kolmogorov definition - you need to describe the program as 
well as its parameters.)

> In this case the only parameter is the starting
> point. Because the total entropy for any PRNG is fixed, the average
> entropy per output bit will always go to zero when you take longer
> output sequences.

Absolutely.

Phil

-- 
Unpatched IE vulnerability: XSS in Unparsable XML Files
Description: Cross-Site Scripting on any site hosting 
             files that can be misrendered in MSXML
Reference: http://sec.greymagic.com/adv/gm013-ie/
Exploit: http://sec.greymagic.com/adv/gm013-ie/