Re: Subtract-and-carry PRNGs

Augustus SFX van Dusen wrote:
> Subtract-and-carry PRNGs are attractive because of their simplicity, and
> because of the fact that they tend to have extremely long periods.
> However, I understand that at least some implementations show poor
> statistical randomness properties. My question is, Are subtract-and-carry
> PRNGs in general prone to have (relatively) poor statistical randomness
> properties? If not, are they cryptographically safe?

If they're anything like a lagged fibonacci generator they're totally
linear. So no, you can't use them directly for cryptographic
purposes.

If you want a secure PRNG you should look into something along the
lines of Yarrow or Fortuna.

Tom
Received on Mon May 1 01:53:35 2006