Re: cprng_fast implementation benchmarks

<[email protected]> Thu, 24 Apr 2014 14:03:32 +0000
Newsgroups gmane.os.netbsd.devel.crypto,gmane.os.netbsd.devel.kernel
Message-ID <[email protected]>
On Apr 23, 2014, at 7:56 PM, Thor Lancelot Simon <[email protected]> wrote:

> On Wed, Apr 23, 2014 at 02:21:31PM +0000, [email protected] wrote:
>> 
>> I?ve been watching this long stream of messages flying by, and I?m a bit concerned about the approach.
>> 
>> As I understand it, there is a strong RNG, based on RC4 (?ARC4?) in the kernel today.
> 
> No.  There is a "strong" RNG, based on the NIST SP800-90 CTR_DRBG with AES128
> as the block transform.
> 
> There is also a "fast" RNG, based on RC4.
> 
> We are discussing the replacement of the "fast" RNG.

Ok. But if that’s a non-strong RNG, why are we discussing security properties?  And why are we considering algorithms this complex, rather than using a PRNG?

In other words, this is being treated like it’s in between a PRNG and a strong RNG.  I don’t understand why there can be a middle ground like that, and what its required properties would be.

	paul