Enigma-style scrambler to beat frauds

Press, 7 February 1986, Page 17

Enigma-style scrambler to beat frauds

From STEVE CONNOR in London

Fraud worth millions of dollars can be perpetrated by wily computer specialists intercepting financial data being'sent down telephone lines from one bank to another. Now their days are numbered. British Telecom, recently privatised and nearly a monopoly, is about to laurich a scrambler that will make the German wartime Enigma system look like Plain English. A team of nine scientists from B.T.’s Martlesham Heath research laboratories has developed a device 'called B-crypt. It will be built into some of B.T.’s own products and the company hopes to make it available to firms that make telecommunications equipment or computers. B-crypt uses an encryption al-

gorith-coding process that B.T. has developed and called 8152. - The team from Martlesham then placed the Bl 52 algorith on to a chip that fits neatly and unobtrusively in a computer terminal. The sender and recipient of the date agree to use a particular code, or “key,” that only they know about. The key and the algorithm in the chip then turn the message into a» cipher that will appear as junk to anyone who intercepts it. The lawful recipient uses a similar key at that other end to decipher the encrypted message. Even if the encryption algor-

ithm is known to a third party, , the transmitted message will re- # main a mystery because the eavesdropper will not know the right key that. the sender and recipient have agreed to use. Just for good measure, the key can be changed at any time, providing both know to what it has been changed to. When there are only two -

people sending and receiving information and. when the key is changed routinely in a pre-deter-mined sequence which is only known by two parties, the system is called a “one-time pad”. This was the method of encryption used by the hot-line between Washington and Moscow, which is a teleprinter and not a telephone as most people think.

B-crypt is not a one-time pad because it is built so that many senders and receivers can use the same system for transmitting their messages. B-crypt is, in theory, possible to crack but only if sufficient computational muscle were to be put into the task — probably beyond every organisation but high-powered governmental decoding stations. The impetus for B.T. to develop B-crypt has also, comp from the difficulty in Europe of obtaining what has until now "been the only encryption chip available for commercial purposes, the Data Encryptian Standard (D.E.S) chip. The patent for DJE.S is held by the American computer company, IBM, and buyers in Europe have to supply extensive details” to the United States Government explaining what the D.E.S. chips will be used for.

Many Eurbpean companies, fearing competition, are understandably reluctant to do this.

t The company says B-crypt is somewhat superior to D.E.S. because, whereas D.E.S. is designed to work best within a computer system, B-crypt is better designed to encrypt information that is transmitted from one computer to another. .Copyright *— London Observer Service.