Re: Which password cipher ?

[Joerg Sonnenberger <joerg%britannica.bec.de@localhost>]

On Tue, Nov 30, 2010 at 05:32:38PM -0500, Steven Bellovin wrote:
> The weaknesses in SHA1 are completely irrelevant here.

Yes.

> The big problem with the traditional DES method is that passwords are
> limited to 8 characters.  The SHA-1 method -- which is really HMAC-SHA1
> method -- does not have any arbitrary limit; this is the one I recommend.

Not exactly true for DES -- it is still way too cheap to crack. One
useful paper on the topic is
http://www.bsdcan.org/2009/schedule/attachments/87_scrypt.pdf

It discusses some of the possible attack vectors. IMO we should make the
Blowfish or SHA1 based cypher the default and not ask. The only case
where the cipher really matters (other than security against cracking)
is interoperability with !NetBSD systems. In that case it only matters
if you want to copy the encrypted password from master.passwd. I believe
you already know how to change the cipher algorithm if you want to do
something like that...

Joerg