SAVILLE is a classified NSA Type 1 encryption algorithm. It is used broadly, often for voice encryption, and implemented in a large number of 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 suggest that SAVILLE has a 128-bit key. On the AIM microchip, it runs at 4% of the clock rate (compare DES at 76% and BATON at 129%). The Cypris chip mentions 2 modes; specifications for Windster and Indictor specify that they provide Saville I.
Some devices and protocols that implement SAVILLE:
- The VINSON family (voice encryption)
- APCO Project 25 (single-channel land mobile radios) (Saville has algorithm ID 04)
- Versatile encryption chips: AIM, Cypris, Sierra I/II, Windster, Indictor, Presidio, Railman
According to cryptomuseum.com
In the Early 1980s, Philips Usfa in Eindhoven (Netherlands) received a first description of SAVILLE, because it was developing its Spendex-40 and Spendex-50 narrow band and wide band secure voice equipment. Unlike before with Aroflex, that used a Philips Usfa designed crypto logic, this time it was decided to implement an existing and already approved NATO crypto logic.
Clearly, this had a number of advantages. First of all interoperability with existing NATO equipment like STU II and VINSON. Secondly, it was anticipated that the NATO approval by SECAN would take much less time, by not having to evaluate the crypto logic.
Rumour had it in those days, that there was a third reason. By implementing SAVILLE in a new national development, the NLNCSA would automatically receive all baseline documentation regarding the crypto logic, which would otherwise not be obvious at all.
Still, to Philips Usfa and its cryptography aware employees it seemed quite peculiar that cryptographic equipment using a foreign, NSA-developed crypto logic, was used to protect top secret information. SAVILLE was implemented in hardware, more precisely in circuits comprising a custom gate array and standard integrated circuits, by Philips Usfa in the first half of the 1980s.