The Navajo I is a secure telephone

Secure voice

Secure voice is a term in cryptography for the encryption of voice communication over a range of communication types such as radio, telephone or IP.-History:...

 built into a briefcase

Briefcase

A briefcase is a narrow box-shaped bag or case used mainly for carrying papers and other documents and equipped with a handle. Lawyers commonly use briefcases to carry briefs to present to a court, hence the name...

 that was developed by the U.S. National Security Agency

National Security Agency

The National Security Agency/Central Security Service is a cryptologic intelligence agency of the United States Department of Defense responsible for the collection and analysis of foreign communications and foreign signals intelligence, as well as protecting U.S...

. According to information on display in 2002 at the NSA's National Cryptologic Museum

National Cryptologic Museum

The National Cryptologic Museum is an American museum of cryptologic history that is affiliated with the National Security Agency . The first public museum in the U.S. Intelligence Community, NCM is located in the former Colony Seven Motel, just two blocks from the NSA headquarters at Fort...

, 110 units were built in the 1980s for use by senior government officials when traveling. It uses the linear predictive coding

Linear predictive coding

Linear predictive coding is a tool used mostly in audio signal processing and speech processing for representing the spectral envelope of a digital signal of speech in compressed form, using the information of a linear predictive model...

 algorithm LPC-10 at 2.4 kilobits/second.

The name is most likely a reference to the Navajo code talkers of World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

.

Source

Display labels from http://www.delusion.org/pix/trips/was-dc/200210/nsa_crypto_museum/.

See also

• STU-II
  STU-II
  The STU-II is a secure telephone developed by the U.S. National Security Agency. It permitted up to six users to have secure communications, on a time-shared basis. It was made by ITT Defense Communications, Nutley, New Jersey...
  
  
• SCIP