STU II (KY-71) Secure Telephone

From Wikipedia:
The STU-II is a secure telephone developed by the National Security Agency. It was made by ITT-Defense Communications, Nutley, New Jersey. An OEM partner was Northern Telecom near Ottawa.

According to information on display in 2005 at the NSA's National Cryptologic Museum, the STU-II was in use from the 1980s to the present. It uses the linear predictive coding algorithm LPC-10 at 2.4 kilobits/second, and the "Key Distribution Center" (KDC) for key management. The display also stated that the STU-II B is the standard narrow band secure telephone.

STU-II replaced the STU-I, KY-3 and the Navajo I. The last was a secure telephone in a briefcase, of which 110 were built in the 1980s for use by senior government officials when traveling. It also used LPC-10.

Some 10 000 STU-II units were produced.

STU II phone set. (Photo courtesy Wikipedia)
STU-II controller in cabinet. (Photo courtesy Wikipedia)



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Jan 10/09