SAVILLE
SAVILLE is a classified NSA Type 1 encryption algorithm, developed in the late 1960s, jointly by the Government Communications Headquarters in the UK and the National Security Agency in the US. It is used broadly, often for voice encryption, and implemented in many encryption devices.
Little is known publicly about the algorithm itself due to its classified nature and inclusion in the NSA's Suite A. Some documentation related to the KYK-13 fill device and statements made by military officials confirm that SAVILLE has a 128-bit key, which consists of 120 key bits and an 8-bit checksum. Furthermore, it is known that SAVILLE has two modes of operation: Autonomous Mode and Autoclave Mode. On the AIM microchip, it runs at 4% of the clock rate. The Cypris chip mentions two modes; specifications for Windster and Indictor specify that they provide Saville I.
Some devices and protocols that implement SAVILLE:
