Some patented or trademarked algorithms were added to mcrypt: IDEA and RC6.
To use these algorithms you may need license from the authors. As far as
I know no license is required for non-commercial use of IDEA.

For detailed patent information on IDEA contact:
         Ascom Systec Ltd.              E-Mail: IDEA@ASCOM.CH
         Gewerbepark                    http://WWW.ASCOM.CH/SYSTEC
         CH-5506 Maegenwil
         Switzerland

For information on RC6 contact:

	RSA Laboratories		http://www.rsa.com
	20 Crosby Drive
	Bedford, MA  01730-1402 - USA
	Phone: 781-687-7057
	Fax: 781-687-7213


After releasing the 2.1.18 version of mcrypt I received the
following feedback, and I agree completely, so these "non-free" algorithms
are enabled by default.

From: gisle@ii.uib.no (Gisle S{lensminde)
To: Nmav@i-net.paiko.gr

In your recent version of mcrypt, you have included algorithms 
that is patented, and is writing that these algorithms can't be 
used without licence. I have a comment on this:

Patenting of ideas is very controvesial, and indeed very few nations 
is accepting patenting on ideas. USA and Japan is one of the few that 
does, and it is indeed not accepted by the international patent 
conventions. Algorithms is ideas in this sense. 

It is a very common misunderstanding that patents on algorithms 
applies outside USA and Japan, but they does not. Since I personally
refuse the idea of patents on ideas, I think it is sad that people 
don't do things that is perfectly legal, only because they _think_ 
it is illegal. It is also a good idea to let the Americans know that 
their stupid laws don't apply elsewhere. I write this, because many
people, including professional cyptographers, don't know better.

Regards, Gisle

--
Gisle Sülensminde ( gisle@ii.uib.no )