Re: [TLS] Comparative cipher suite strengths

["Steven M. Bellovin" <smb at cs.columbia.edu>]

On Thu, 30 Apr 2009 18:56:35 -0700
Bill Frantz <frantz at pwpconsult.com> wrote:

> When I think of the reasons that NSA/DOD could have for requiring
> AES-128 for secret and AES-192 for top secret, I think they may be
> looking at the whole cryptographic system. While symmetric cyphers
> have some solid math behind them, other parts of the system, such as
> generating random numbers for the keys are frequently more akin to
> black magic.
> 
From http://catless.ncl.ac.uk/Risks/15.48.html#subj1

	The unit key is generated via Skipjack itself, from random
	seeds provided by the two escrow agencies (approximately
	monthly, though that isn't certain yet).  They say they prefer
	a software generation process because its correct behavior is
	auditable.

In other words, the NSA understands that keys should not be generated
by a random process.

		--Steve Bellovin, http://www.cs.columbia.edu/~smb