[Dovecot] Secure authentication?

[Timothy Murphy]

On Sun 11 Nov 2007, Jürgen Herz wrote:
> On 2007-11-11 01:13, Bjørn T Johansen wrote:
> > I have enabled SSL support for my dovecot installation but if I enable
> > secure authentication in my MUA, I get an error from dovecot telling me
> > that this is not supported..
> >
> > Is this because dovecot does not support this or am I missing some
> > config?
>
> Might be. But note that with "secure authentication" it might mean
> CRAM-MD5, DIGEST-MD5, Kerberos a.s.o. that are no simple plain text or
> just Base64 coding mechanisms. SSL on the other hand is a way to make a
> secure *connection*.
> So make sure some of the above mechanisms are enabled in your dovecot
> installation as well.

Apologies for a very ignorant question,
but I am puzzled by authentication generally in Linux.
Eg does one have to choose between CRAM-MDS, etc.
Could I just ignore them all if I use SSL?

Is there a clear and simple document on authentication in Linux?