🚀 go-pugleaf

In the following 3 postings I make available (as requested by high
number of people) the description of Xuejia Lai's (and J.L. Masseys)
IDEA-Algorithm (also known as IPES). This corresponds to a chapter
of Mr. Lai's doctorate thesis and is also known as a paper:
  1) Xuejia Lai, "Detailed Description and a Software Implementation of 
     the IPES Cipher", Institute for Signal and Information
     Processing, ETH-Zentrum, Zurich, Switzerland, 1991

The description contains a detailed explanation of en- & deciphering,
the key schedule, the IDEA cipher seen as a set of group-operations,
and states some provable security features of the idea cipher. At the
end an implementation is given.

Please remark that I post this postscript-file with permission of
Xuejia Lai, and that there is a Swiss Patent on it, (I do not know
if there are others) which allows non-commercial use of IDEA.
Please remark also that, although I am posting this in my own respon-
sability, I did not(have part/was allied to/knew about) the creation
of this algorithm until I saw it in a publicly available software.
(Thanks to Mr. Zimmermann here!)

As I asked Mr. Lai about the article of 'Dr. Sidelnikov V.M.' he told
me that he had read it, but found no facts in it, that would enforce
or just back up Dr. Sidelnikov's statements about IDEA. He seemed not
very concerned, found it amazing, that the whole article gave some exact
numbers, but no explanation how they were achieved. But I am sure, Mr.
Lai will speak for himself sooner or later...\

Friendly greetings,
	Germano Caronni


-- 
Instruments register only through things they're designed to register.
Space still contains infinite unknowns.

Germano Caronni    caronni@nessie.cs.id.ethz.ch