Making secure calls faster

A secure telephone is only one type of encryption device the government needs.

Michael Jacobs, director of information assurance at the National Security Agency, keeps two secure phones in his office—a third-generation Standard Telephone Unit (STU-III) and a newer secure phone known as the Standard Telephone Equipment (STE).

The first-generation Standard Telephone Unit was introduced in 1970, according to the STU-III handbook for industry. The phone system stores a unique sequence of random bits for encoding, decoding and authenticating information, a function activated by a key-shaped piece of plastic with an embedded computer chip that is inserted into a slot in the telephone.

STU-III has been out of production for about a year and is slowly being replaced by the STE, which has been in production for the past three years.

STE is built for and works best in an all-digital environment, whereas STU-III is an analog device. When STU-III rings, callers insert their key devices, push a button and wait 15 to 20 seconds for the two phones to exchange encryption codes. The delay "is a nuisance" and can be even longer if one caller is in a country with a less sophisticated telecommunications infrastructure, Jacobs said.

STE, however, is automatically secure if both callers are using STE systems and the phones exchange codes in the time it takes to pick up the ringing telephone.

"The real advantage is that in that [secure] environment, there's substantial improvement in voice quality, and the time to go secure is almost invisible to the customer," Jacobs said. STE "goes automatically secure in that instance, and you have to do something to make it unsecure. [STU-III] goes unsecure, and you have to do something to make it secure."