Title:   Hardware Implementation of IDEA (International Data Encryption Algorithm)

Members: Gerald Lai <laige@ece.orst.edu>

Abstract:

In 1973, the National Bureau of Standards (NBS, now known as the
National Institute of Standards and Technology, or NIST) selected
the Data Encryption Algorithm (DEA, later known as DES) to serve
as a common standard. DES was designed at the IBM TJ Watson Research
Center at the request of the NBS for protecting sensitive data.

It is a block cipher operating on a 64-bit plaintext to produce a
64-bit ciphertext. The symmetric key used is a 56-bit encryption
key that was strong at the time. In other words, there are
72,057,594,037,927,936 (or 2 to the 56th power) possible combinations
of keys. It was claimed that a message encrypted with DES would take
an immensely long time to crack.

Yet, despite its sophistication, many future attempts at cracking DES
showed significant signs of success. For example, the distributive
computing approach of spreading cracking computation power over the
Internet earned Rocke Verser and Michael Sanders the prize of the 1997
DES Challenge. DES Challenge II was also cracked the following year.
With the invention of the Electronic Frontier Foundation DES Cracker,
it was shown that a 56-bit key protection is insufficient against
exhaustive search employed with today's technology. Therefore, there
was an urgent call for a stronger secret-key encryption algorithm.
IDEA was one of the algorithms to answer that call.

The International Data Encryption Algorithm (IDEA) was developed in
Zurich, Switzerland by James Massey and Xuejia Lai and published in
1990. It operates on 64-bit plaintext and ciphertext blocks with a
128-bit key. IDEA is used by the popular program Pretty Good Privacy
(PGP) to encrypt files and electronic mail. Unfortunately, wider use
of IDEA has been hampered by a series of software patents on the
algorithm, which is currently held until 2011 by Ascom-Tech AG in
Solothurn, Switzerland. MediaCrypt offers a royalty-free license for
non-commercial use.

IDEA is somewhat different from the rest of the symmetric key encryption
algorithms in that it uses algebraic operations completely and does
without table lookup methods. It employs a modified 4-word Feistel style
round function system. The strength of IDEA lies in its modulo
multiplication operations and therefore, it relies heavily on modular
inversion.

In this project, I will design a hardware implementation of IDEA using
VHDL. The implementation will be simulated using Mentor Graphics tools.
The demonstration system will be available on the web.