Re: Mousepad RNG's?

> At 8:13 PM -0700 9/27/96, James A. Donald wrote:
> 
>Some time ago, at a cypherpunks conference, people were making
>all sorts of ridiculous proposals for being really, really,
>really, sure that you had real entropy, and a prominent
>cypherpunk, possibly Tim May, said, "This is ridiculous:
>Nobody ever broke good crypto through weakness in the
>source of truly random numbers".  Sometime after that
>Netscape was broken through weakness in the source of
>truly random numbers.

This is correct only in the first part, it is true that good 
cryptography has never been documentably broken through weaknesses in 
a real random source.

The netscape attack was on the PRNG used in netscape, the proverbial 
state of sin. I don`t know what PRNG netscape used in the broken 
version, can anyone tell me what they used, and whether it was the 
PRNG or the seed that was weak, also I would be interested to know 
what they are using now in terms of the algorithm and seed...

 

  Datacomms Technologies web authoring and data security
       Paul Bradley, Paul@fatmans.demon.co.uk
  Paul@crypto.uk.eu.org, Paul@cryptography.uk.eu.org    
       Http://www.cryptography.home.ml.org/
      Email for PGP public key, ID: 5BBFAEB1
     "Don`t forget to mount a scratch monkey"

paul@fatmans.demon.co.uk wrote:
 
> I don`t know what PRNG netscape used in the broken
> version, can anyone tell me what they used, and whether it was the
> PRNG or the seed that was weak

The problem was with the seed; it was especially vulnerable to attacks
from somebody running on the same machine. Sufficient entropy is now
obtained during initialization and the PRNG is reseeded reasonably often
during execution. For the Navigator, this is every time the user event
loop cycles.

> also I would be interested to know
> what they are using now in terms of the algorithm and seed...

A pointer to the fixed code was posted to cypherpunks last year.

PK
--
Philip L. Karlton			karlton@netscape.com
Principal Curmudgeon			http://www.netscape.com/people/karlton
Netscape Communications Corporation

    Everything should be made as simple as possible, but not simpler.
	-- Albert Einstein