USAGE

 To use these extension modules add the following lines to ~/.gnupg/options

	load-extension rsa
	load-extension idea

 You can add these lines to /usr/share/gnupg/options.skel which is copied
 to ~/.gnupg/options for new users.

 With these modules installed gnupg can decrypt messages created by any
 version of pgp.  Messages encrypted to RSA keys by gnupg can be decrypted 
 by pgp 5.x but not by pgp 2.x because gnupg use a newer packet format.

LEGAL

 ATTENTION: This code should not be exported to the United States
 nor should it be used there without a license agreement with PKP.
 The RSA algorithm is protected by U.S. Patent #4,405,829 which
 expires on September 20, 2000!

 The IDEA algorithm is patented by Ascom Systec Ltd. of CH-5506 Maegenwil,
 Switzerland, who allow it to be used on a royalty-free basis for certain
 non-profit applications.  Commercial users must obtain a license from the
 company in order to use IDEA.	IDEA may be used on a royalty-free basis under
 the following conditions:

 Free use for private purposes:

 The free use of software containing the algorithm is strictly limited to non
 revenue generating data transfer between private individuals, ie not serving
 commercial purposes.  Requests by freeware developers to obtain a
 royalty-free license to spread an application program containing the
 algorithm for non-commercial purposes must be directed to Ascom.

 Special offer for shareware developers:

 There is a special waiver for shareware developers.  Such waiver eliminates
 the upfront fees as well as royalties for the first US$10,000 gross sales of
 a product containing the algorithm if and only if:

 1. The product is being sold for a minimum of US$10 and a maximum of US$50.
 2. The source code for the shareware is available to the public.

 Special conditions for research projects:

 The use of the algorithm in research projects is free provided that it serves
 the purpose of such project and within the project duration.  Any use of the
 algorithm after the termination of a project including activities resulting
 from a project and for purposes not directly related to the project requires
 a license.

 Ascom Tech requires the following notice to be included for freeware
 products:

 This software product contains the IDEA algorithm as described and claimed in
 US patent 5,214,703, EPO patent 0482154 (covering Austria, France, Germany,
 Italy, the Netherlands, Spain, Sweden, Switzerland, and the UK), and Japanese
 patent application 508119/1991, "Device for the conversion of a digital block
 and use of same" (hereinafter referred to as "the algorithm").  Any use of
 the algorithm for commercial purposes is thus subject to a license from Ascom
 Systec Ltd. of CH-5506 Maegenwil (Switzerland), being the patentee and sole
 owner of all rights, including the trademark IDEA.

 Commercial purposes shall mean any revenue generating purpose including but
 not limited to:

 i) Using the algorithm for company internal purposes (subject to a site
    license).

 ii) Incorporating the algorithm into any software and distributing such
     software and/or providing services relating thereto to others (subject to
     a product license).

 iii) Using a product containing the algorithm not covered by an IDEA license
      (subject to an end user license).

 All such end user license agreements are available exclusively from Ascom
 Systec Ltd and may be requested via the WWW at http://www.ascom.ch/systec or
 by email to idea@ascom.ch.

 Use other than for commercial purposes is strictly limited to non-revenue
 generating data transfer between private individuals.	The use by government
 agencies, non-profit organizations, etc is considered as use for commercial
 purposes but may be subject to special conditions.  Any misuse will be
 prosecuted.

LICENSE

	Copyright (c) 1997,1998,1999 by Werner Koch (dd9jn)

 Permission is hereby granted, free of charge, to any person obtaining a
 copy of this software and associated documentation files (the "Software"),
 to deal in the Software without restriction, including without limitation
 the rights to use, copy, modify, merge, publish, distribute, sublicense,
 and/or sell copies of the Software, and to permit persons to whom the
 Software is furnished to do so, subject to the following conditions:

 The above copyright notice and this permission notice shall be included in
 all copies or substantial portions of the Software.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 WERNER KOCH BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

 Except as contained in this notice, the name of Werner Koch shall not be
 used in advertising or otherwise to promote the sale, use or other dealings
 in this Software without prior written authorization from Werner Koch.

CREDITS

 The IDEA code herein has been taken from:
   Bruce Schneier: Applied Cryptography. John Wiley & Sons, 1996.
   ISBN 0-471-11709-9. .

