Cryptographic solutions for voice telephony and GSM
Fred C. Piper, Michael John WALKER · Network Security · 1998
In this article we focus attention on the use of cryptography to provide security for GSM. Since the start of public services, security has always been an issue for mobile telephones. Shortly after their introduction, articles appeared in the press reporting that frequency scanners had been used to overhear calls made by celebrities, and cellular operators were reported to be losing millions of pounds a year through fraudulent use of ‘re-chipped mobiles’, telephones which have had their identities changed in such a way that the cost of calls made using them appear on another customers' bills.