Deutsche Telekom AG has developed its own operating system for Smart Cards and claims that it has won the highest security level ever granted to a Smart Card. Called TCOS, for Telekom Card Operating System, it runs on a Smart Card encapsulating a Siemens AG cryptocontroller. Cards running TCOS will be used for access control and other high-level security applications in telecommunications networks, for electronic-commerce and local personal computer security. The card has won E4 certification and Telekom says the award is the outcome of a joint project with Siemens’ Semiconductor Group to integrate the full security control functionality of TCOS using Siemens’ cryptocontroller security architecture. The card uses the Siemens SLE 44CR80S controller, which combines 17Kb of ROM, 8Kb of EEPROM and 256 bytes of internal RAM with a 540-bit calculation unit for rapid processing of asymmetric cryptoalgorithms. Smart Cards with earlier versions of TCOS have been in practical use since 1994.