MISTY Mystery Tour

Diffie/ Hellman's Public
Key Cryptography

ARP Anet's Whitfield Diffie of the US became the architect of the Internet when he predicted that large numbers of people would connect their computer with phone lines and communicate with electronic mail. He also predicted that a new code would be necessary to protect the privacy of users. Along with Martin Hellman of Stanford University, he proceeded to invent a new idea known as the "public key". What makes public key ciphers different is that they have two keys. One is "public", available to anyone, and can be used to encipher a message. The other is "private", known only to one person and can be used to decipher a message.

America's standard
algorithm, DES

In 1973, the American National Bureau of Standards (NBS) published a notice in the Federal Register soliciting proposals for cryptographic algorithms to protect data during transmission and storage. An encryption named Data Encryption Standard (DES) was an improved version of the algorithm "Lucifer" developed by Horst Feistel of the Thomas J. Watson Laboratory at IBM, and was officially adopted as the Federal Information Processing Standard (FIPS).

In the subsequent 15 years, a countless number of researchers were challenged, unsuccessfully, to decipher the DES.

RSA algorithm

Ron Rivest, Adi Shamir, and Leonard Adleman from the Massachusetts Institute of Technology, invented the computation method. That became the central theme for developing "public keys", invented by Deffie/ Hellman. This public key was named the "RSA algorithm" after the initials of the 3 developers.

Reference: 1973 Public Key for GCHQ
James Ellis of the Government Communications Headquarters (GCHQ), an intelligence and security organization established in the UK after WW2, had invented a similar theory in 1973. This was not disclosed to the public until recently, four years prior to the announcement of the RSA public key.

Deciphering DES

DES is the encryption algorithm adopted by the American National Bureau of Standards in 1977. DES uses a 54-bit key, which enables 70 quadrillion (10,000 x 7 trillion) combinations. It was assumed that DES was impenetrable, and it remained so for 15 years.
However, researcher Mitsuru Matsui of Mitsubishi Electric succeeded, single-handedly, in breaking this code and shocked cryptographers all over the world.

>> More about MISTY

Birth of KASUMI, the standard encryption
method for 3rd generation mobile phones

More and more information systems and products such as IC cards used in e-commerce are adopting “MISTY”.

In 2000, the international standard encryption for mobile phones based on MISTY technology, named "KASUMI" was developed to focus on the encryption algorithm for third generation mobile phones.