The

National Security Agency The National Security Agency (NSA) is an intelligence agency of the United States Department of Defense, under the authority of the director of national intelligence (DNI). The NSA is responsible for global monitoring, collection, and proces ...

took over responsibility for all

US government The Federal Government of the United States of America (U.S. federal government or U.S. government) is the national government of the United States. The U.S. federal government is composed of three distinct branches: legislative, execut ...

encryption In Cryptography law, cryptography, encryption (more specifically, Code, encoding) is the process of transforming information in a way that, ideally, only authorized parties can decode. This process converts the original representation of the inf ...

systems when it was formed in 1952. The technical details of most NSA-approved systems are still

classified Classified may refer to: General *Classified information, material that a government body deems to be sensitive *Classified advertising or "classifieds" Music *Classified (rapper) (born 1977), Canadian rapper * The Classified, a 1980s American ro ...

, but much more about its early systems have become known and its most modern systems share at least some features with commercial products. NSA and its predecessors have produced a number of cipher devices.

Rotor machine In cryptography, a rotor machine is an electro-mechanical stream cipher device used for encrypting and decrypting messages. Rotor machines were the cryptographic state-of-the-art for much of the 20th century; they were in widespread use from ...

s from the 1940s and 1950s were mechanical marvels. The first generation electronic systems were quirky devices with cantankerous

punched card A punched card (also punch card or punched-card) is a stiff paper-based medium used to store digital information via the presence or absence of holes in predefined positions. Developed over the 18th to 20th centuries, punched cards were widel ...

readers for loading keys and failure-prone, tricky-to-maintain

vacuum tube A vacuum tube, electron tube, thermionic valve (British usage), or tube (North America) is a device that controls electric current flow in a high vacuum between electrodes to which an electric voltage, potential difference has been applied. It ...

circuitry. Late 20th century systems are just

black box In science, computing, and engineering, a black box is a system which can be viewed in terms of its inputs and outputs (or transfer characteristics), without any knowledge of its internal workings. Its implementation is "opaque" (black). The te ...

es, often literally. In fact they are called '' blackers'' in NSA parlance because they convert

plaintext In cryptography, plaintext usually means unencrypted information pending input into cryptographic algorithms, usually encryption algorithms. This usually refers to data that is transmitted or stored unencrypted. Overview With the advent of comp ...

classified signals (''red'') into encrypted unclassified

ciphertext In cryptography, ciphertext or cyphertext is the result of encryption performed on plaintext using an algorithm, called a cipher. Ciphertext is also known as encrypted or encoded information because it contains a form of the original plaintext ...

signals (''black''). They typically have

electrical connector Components of an electrical circuit are electrically connected if an electric current can run between them through an electrical conductor. An electrical connector is an electromechanical device used to create an electrical connection between ...

s for the red signals, the black signals, electrical power, and a port for loading keys. Controls can be limited to selecting between key fill, normal operation, and diagnostic modes and an all important '' zeroize'' button that erases

classified information Classified information is confidential material that a government deems to be sensitive information which must be protected from unauthorized disclosure that requires special handling and dissemination controls. Access is restricted by law or ...

including keys and perhaps the encryption algorithms. 21st century systems often contain all the sensitive cryptographic functions on a single, tamper-resistant integrated circuit that supports multiple algorithms and allows over-the-air or network re-keying, so that a single hand-held field radio, such as the AN/PRC-148 or AN/PRC-152, can interoperate with most current NSA

cryptosystem In cryptography, a cryptosystem is a suite of cryptographic algorithms needed to implement a particular security service, such as confidentiality (encryption). Typically, a cryptosystem consists of three algorithms: one for key generation, one ...

s. Little is publicly known about the algorithms NSA has developed for protecting

, called Type 1 algorithms by the agency. In 2003, for the first time in its history, NSA-approved two published algorithms, Skipjack and AES, for Type 1 use in NSA-approved systems.

Security factors

NSA has to deal with many factors in ensuring the security of communication and information ( COMSEC and INFOSEC in NSA jargon): *

Confidentiality Confidentiality involves a set of rules or a promise sometimes executed through confidentiality agreements that limits the access to or places restrictions on the distribution of certain types of information. Legal confidentiality By law, la ...

: making sure messages cannot be read by unauthorized parties. *

Authentication Authentication (from ''authentikos'', "real, genuine", from αὐθέντης ''authentes'', "author") is the act of proving an Logical assertion, assertion, such as the Digital identity, identity of a computer system user. In contrast with iden ...

: the validation of the source of transmitted messages. * Nonrepudiation: making sure that transmitted messages cannot be forged. * Traffic flow security: making sure an adversary cannot obtain information from

traffic analysis Traffic analysis is the process of intercepting and examining messages in order to deduce information from patterns in communication. It can be performed even when the messages are encrypted. In general, the greater the number of messages observ ...

, often accomplished by link encryption. *

Key management Key management refers to management of Key (cryptography), cryptographic keys in a cryptosystem. This includes dealing with the generation, exchange, storage, use, crypto-shredding (destruction) and replacement of keys. It includes cryptographic ...

: getting keys securely to thousands of cipher devices in the field, perhaps the most difficult part of implementing an encryption system. One NSA goal is benign fill, a technology for distributing keys in a way that the humans never have access to plaintext key. * Investigative access: making sure encrypted communications are accessible to the US government. While few would argue with the need for the government to access its own internal communications, the NSA Clipper chip proposal to extend this key escrow requirement to public use of cryptography was highly controversial. * TEMPEST: protecting

from compromise by electronic, acoustic, or other emanations. *

Tamper resistance Tamperproofing is a methodology used to hinder, deter or detect unauthorised access to a device or circumvention of a security system. Since any device or system can be foiled by a person with sufficient knowledge, equipment, and time, the term " ...

tamper-evident Tamper-evident describes a device or process that makes unauthorized access to the protected object easily detected. Seals, markings, or other techniques may be tamper indicating. Tampering Tampering involves the deliberate altering or adulterat ...

self-destruct A self-destruct is a mechanism that can cause an object to destroy itself or render itself inoperable after a predefined set of circumstances has occurred. Self-destruct mechanisms are typically found on devices and systems where malfunction coul ...

: ensuring security even if cipher devices are physically accessed without authorization or are captured. * Meeting military specifications for size, weight, power consumption, mean time between failures, and ruggedness for use in mobile platforms. * Ensuring compatibility with military and commercial communication standards. *

Electromagnetic pulse An electromagnetic pulse (EMP), also referred to as a transient electromagnetic disturbance (TED), is a brief burst of electromagnetic energy. The origin of an EMP can be natural or artificial, and can occur as an electromagnetic field, as an ...

hardening: protecting against

nuclear explosion A nuclear explosion is an explosion that occurs as a result of the rapid release of energy from a high-speed nuclear reaction. The driving reaction may be nuclear fission or nuclear fusion or a multi-stage cascading combination of the two, th ...

effects, particularly

electromagnetic pulse An electromagnetic pulse (EMP), also referred to as a transient electromagnetic disturbance (TED), is a brief burst of electromagnetic energy. The origin of an EMP can be natural or artificial, and can occur as an electromagnetic field, as an ...

. * Controlling cost: making sure encryption is affordable so units that need it have it. There are many costs beyond the initial purchase price, including the manpower to operate and maintain the systems and to ensure their security and the cost of key distribution. * Enabling secure communication with allied forces without compromising secret methods.

Five generations of NSA encryption

The large number of cipher devices that NSA has developed in its half century of operation can be grouped into five generations (decades given are very approximate):

First generation: electromechanical

First generation NSA systems were introduced in the 1950s and were built on the legacy of NSA's

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

predecessors and used rotor machines derived from the SIGABA design for most high level encryption; for example, the KL-7. Key distribution involved distribution of paper key lists that described the rotor arrangements, to be changed each day (the ''

cryptoperiod A cryptoperiod is the time span during which a specific cryptographic key is authorized for use. Common government guidelines range from 1 to 3 years for asymmetric cryptography, and 1 day to 7 days for symmetric cipher traffic keys. Factors to co ...

'') at midnight, GMT. The highest level traffic was sent using one-time tape systems, including the British

5-UCO The 5-UCO (5-Unit Controlled)Ralph Erskine, "The 1944 Naval BRUSA Agreement and its Aftermath", ''Cryptologia'' 30(1), January 2006 pp14–15 was an on-line one-time tape Vernam cipher encryption system developed by the UK during World War II ...

, that required vast amounts of paper tape keying material.

Second generation: vacuum tubes

Second generation systems (1970s) were all electronic designs based on

s and transformer logic. Algorithms appear to be based on

linear-feedback shift register In computing, a linear-feedback shift register (LFSR) is a shift register whose input bit is a Linear#Boolean functions, linear function of its previous state. The most commonly used linear function of single bits is exclusive-or (XOR). Thus, ...

s, perhaps with some non-linear elements thrown in to make them more difficult to cryptanalyze. Keys were loaded by placing a

in a locked reader on the front panel.Melville Klein, "Securing Record Communications: The TSEC/KW-26", 2003, NSA brochure, p. 4
(PDF)
/ref> The cryptoperiod was still usually one day. These systems were introduced in the late 1960s and stayed in use until the mid-1980s. They required a great deal of care and maintenance, but were not vulnerable to EMP. The discovery of the Walker spy ring provided an impetus for their retirement, along with remaining first generation systems.

Third generation: integrated circuits

Third generation systems (1980s) were transistorized and based on

integrated circuit An integrated circuit (IC), also known as a microchip or simply chip, is a set of electronic circuits, consisting of various electronic components (such as transistors, resistors, and capacitors) and their interconnections. These components a ...

s and likely used stronger algorithms. They were smaller and more reliable. Field maintenance was often limited to running a diagnostic mode and replacing a complete bad unit with a spare, the defective cipher device being sent to a depot for repair. Keys were loaded through a connector on the front panel. NSA adopted the same type of connector that the military used for field radio handsets as its fill connector. Keys were initially distributed as strips of

punched paper tape Punch commonly refers to: * Punch (combat), a strike made using the hand closed into a fist * Punch (drink), a wide assortment of drinks, non-alcoholic or alcoholic, generally containing fruit or fruit juice Punch may also refer to: Places * ...

that could be pulled through a hand held reader ( KOI-18) connected to the fill port. Other, portable electronic fill devices ( KYK-13, etc.) were available as well.

Fourth generation: electronic key distribution

Fourth generation systems (1990s) use more commercial packaging and electronic key distribution. Integrated circuit technology allowed backward compatibility with third generation systems.

Security token A security token is a peripheral device used to gain access to an electronically restricted resource. The token is used in addition to, or in place of, a password. Examples of security tokens include wireless key cards used to open locked door ...

s, such as the KSD-64 crypto ignition key (CIK) were introduced. Secret splitting technology allows encryptors and CIKs to be treated as unclassified when they were separated. Later the Fortezza card, originally introduced as part of the controversial Clipper chip proposal, were employed as tokens. Cryptoperiods were much longer, at least as far as the user was concerned. Users of secure telephones like the

STU-III STU-III (Secure Telephone Unit - third generation) is a family of secure telephones introduced in 1987 by the NSA for use by the United States government, its contractors, and its allies. STU-III desk units look much like typical office telephon ...

only have to call a special phone number once a year to have their encryption updated. Public key methods (

FIREFLY The Lampyridae are a family of elateroid beetles with more than 2,000 described species, many of which are light-emitting. They are soft-bodied beetles commonly called fireflies, lightning bugs, or glowworms for their conspicuous production ...

) were introduced for electronic key management ( EKMS), which employed a commercial or militarized personal computer running

MS-DOS MS-DOS ( ; acronym for Microsoft Disk Operating System, also known as Microsoft DOS) is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few op ...

to generate cryptographic keys and signal operating instructions (SOI/CEOI). An NSA-supplied AN/CSZ-9

hardware random number generator In computing, a hardware random number generator (HRNG), true random number generator (TRNG), non-deterministic random bit generator (NRBG), or physical random number generator is a device that generates random numbers from a physical process c ...

produced the needed random bits. The CSZ-9 connects to the PC through an RS-232 port and is powered by five D cell (BA-30) batteries. In later phases of EKMS, the random data functionality is included in an NSA key processor (KP). Keys could now be generated by individual commands instead of coming from NSA by courier. A common handheld fill device (the AN/CYZ-10) was introduced to replace the plethora of devices used to load keys on the many third generation systems that were still widely used. Encryption support was provided for commercial standards such as

Ethernet Ethernet ( ) is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 198 ...

, IP (originally developed by DOD's ARPA), and optical fiber multiplexing. Classified networks, such as

SIPRNet The Secret Internet Protocol Router Network (SIPRNet) is "a system of interconnected computer networks used by the U.S. Department of Defense and the U.S. Department of State to transmit classified information (up to and including information ...

(Secret Internet Protocol Router Network) and JWICS (Joint Worldwide Intelligence Communications System), were built using commercial

Internet The Internet (or internet) is the Global network, global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a internetworking, network of networks ...

technology with secure communications links between "enclaves" where classified data was processed. Care had to be taken to ensure that there were no insecure connections between the classified networks and the public

Fifth generation: network-centric systems

In the twenty-first century, communication is increasingly based on computer networking. Encryption is just one aspect of protecting sensitive information on such systems, and far from the most difficult one. NSA's role will increasingly be to provide guidance to commercial firms designing systems for government use. HAIPE solutions are examples of this type of product (e.g.
KG-245A
an
KG-250
. Other agencies, particularly

NIST The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into physical s ...

, have taken on the role of supporting security for commercial and sensitive but unclassified applications. NSA's certification of the unclassified NIST-selected AES algorithm for classified use "in NSA-approved systems" suggests that, in the future, NSA may use more non-classified algorithms. The KG-245A and KG-250 use both classified and unclassified algorithms. The NSA Information Assurance Directorate is leading the Department of Defense

Cryptographic Modernization Program The Cryptographic Modernization Program is a United States Department of Defense, Department of Defense directed, NSA Information Assurance Directorate led effort to transform and modernize Information Assurance capabilities for the 21st century. ...

, an effort to transform and modernize Information Assurance capabilities for the 21st century. It has three phases: * Replacement: Replace all devices at risk. * Modernization: Integrate modular programmable/embedded crypto solutions. * Transformation: Be compliant with Global Information Grid/NetCentric requirements. NSA has helped develop several major standards for secure communication: the ''Future Narrow Band Digital Terminal (

FNBDT The Secure Communications Interoperability Protocol (SCIP) is a US standard for secure voice and data communication, focircuit-switchedone-to-one connections, not packet-switched networks. SCIP derived from the US Government Future Narrowband Di ...

)'' for voice communications, ''High Assurance Internet Protocol Interoperability Encryption- Interoperability Specification ( HAIPE)'' for computer networking and Suite B encryption algorithms.

NSA encryption by type of application

The large number of cipher devices that NSA has developed can be grouped by application:

Record traffic encryption

During

, written messages (known as record traffic) were encrypted off line on special, and highly secret,

rotor machine In cryptography, a rotor machine is an electro-mechanical stream cipher device used for encrypting and decrypting messages. Rotor machines were the cryptographic state-of-the-art for much of the 20th century; they were in widespread use from ...

s and then transmitted in five-letter code groups using

Morse code Morse code is a telecommunications method which Character encoding, encodes Written language, text characters as standardized sequences of two different signal durations, called ''dots'' and ''dashes'', or ''dits'' and ''dahs''. Morse code i ...

teletypewriter A teleprinter (teletypewriter, teletype or TTY) is an electromechanical device that can be used to send and receive typed messages through various communications channels, in both point-to-point and point-to-multipoint configurations. Init ...

circuits, to be decrypted off-line by similar cipher devices at the other end. The SIGABA rotor machine, developed during this era continued to be used until the mid-1950s, when it was replaced by the KL-7, which had more rotors. The

KW-26 The TSEC/KW-26, code named ROMULUS, was an encryption system used by the U.S. Government and, later, by NATO countries. It was developed in the 1950s by the National Security Agency (NSA) to secure fixed teleprinter circuits that operated 24 ho ...

ROMULUS was a second generation cipher device in wide use that could be inserted into teletypewriter circuits so traffic was encrypted and decrypted automatically. It used electronic

shift registers A shift register is a type of digital circuit using a cascade of flip-flops where the output of one flip-flop is connected to the input of the next. They share a single clock signal, which causes the data stored in the system to shift from one loca ...

instead of rotors and became very popular (for a COMSEC device of its era), with over 14,000 units produced. It was replaced in the 1980s by the more compact KG-84, which in turn was superseded by the KG-84-interoperable KIV-7.

Fleet broadcast

US Navy ships traditionally avoid using their radios to prevent adversaries from locating them by

direction finding Direction finding (DF), radio direction finding (RDF), or radiogoniometry is the use of radio waves to determine the direction to a radio source. The source may be a cooperating radio transmitter or may be an inadvertent source, a naturall ...

. The Navy also needs to maintain traffic security, so it has radio stations constantly broadcasting a stream of coded messages. During and after World War II, Navy ships copied these ''fleet broadcasts'' and used specialized ''

call sign In broadcasting and radio communications, a call sign (also known as a call name or call letters—and historically as a call signal—or abbreviated as a call) is a unique identifier for a transmitter station. A call sign can be formally as ...

encryption'' devices to figure out which messages were intended for them. The messages would then be decoded off line using SIGABA or KL-7 equipment. The second generation KW-37 automated monitoring of the fleet broadcast by connecting in line between the radio receiver and a

teleprinter A teleprinter (teletypewriter, teletype or TTY) is an electromechanical device that can be used to send and receive typed messages through various communications channels, in both point-to-point (telecommunications), point-to-point and point- ...

. It, in turn, was replaced by the more compact and reliable third generation KW-46.

Strategic forces

NSA has the responsibility to protect the command and control systems for nuclear forces. The KG-3X series is used in the US government's ''Minimum Essential Emergency Communications Network'' and the ''Fixed Submarine Broadcast System'' used for transmission of emergency action messages for nuclear and national command and control of US strategic forces. The Navy is replacing the KG-38 used in

nuclear submarine A nuclear submarine is a submarine powered by a nuclear reactor, but not necessarily nuclear-armed. Nuclear submarines have considerable performance advantages over "conventional" (typically diesel-electric) submarines. Nuclear propulsion ...

s with KOV-17 circuit modules incorporated in new long-wave receivers, based on commercial VME packaging. In 2004, the US Air Force awarded contracts for the initial system development and demonstration (SDD) phase of a program to update these legacy generation systems used on aircraft.

Trunk encryption

Modern communication systems

multiplex Multiplex may refer to: Science and technology * Multiplex communication, combining many signals into one transmission circuit or channel ** Multiplex (television), a group of digital television or radio channels that are combined for broadcast * ...

many signals into wideband data streams that are transmitted over

optical fiber An optical fiber, or optical fibre, is a flexible glass or plastic fiber that can transmit light from one end to the other. Such fibers find wide usage in fiber-optic communications, where they permit transmission over longer distances and at ...

coaxial cable Coaxial cable, or coax (pronounced ), is a type of electrical cable consisting of an inner Electrical conductor, conductor surrounded by a concentric conducting Electromagnetic shielding, shield, with the two separated by a dielectric (Insulat ...

microwave Microwave is a form of electromagnetic radiation with wavelengths shorter than other radio waves but longer than infrared waves. Its wavelength ranges from about one meter to one millimeter, corresponding to frequency, frequencies between 300&n ...

relay, and

communication satellite A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth. ...

s. These wide-band circuits require very fast cipher devices. The WALBURN family ( KG-81, KG-94/ 194, KG-94A/ 194A, KG-95) of equipment consists of high-speed bulk encryption devices used primarily for microwave trunks, high-speed land-line circuits, video teleconferencing, and T-1 satellite channels. Another example is the KG-189, which support

SONET Synchronous Optical Networking (SONET) and Synchronous Digital Hierarchy (SDH) are standardized protocols that transfer multiple digital bit streams synchronously over optical fiber using lasers or highly coherent light from light-emitting diodes ...

optical standards up to 2.5 Gbit/s. Digital Data encryptors such as KG-84 family which includes the TSEC/ KG-84, TSEC/ KG-84A and TSEC/ KG-82, TSEC/ KG-84A and TSEC/ KG-84C, also the KIV-7.

KIV-7

The KIV-7 is a

Type-1, single-channel encryptor originally designed in the mid-1990s by

AlliedSignal AlliedSignal, Inc. was an American aerospace, automotive and engineering company, created through the 1985 merger of Allied Corp. and The Signal Companies. It purchased Honeywell for $14.8 billion in 1999, and adopted the Honeywell name and iden ...

Corporation to meet the demand for secure data communications from personal computers (PC), workstations, and FAXs. It has data rates up to 512 kbit/s and is interoperable with the KG-84, KG-84A, and KG-84C data encryption devices. Several versions of the KIV-7 have been developed over the years by many different corporations that have either bought the rights to build the KIV-7 or through corporate mergers. *KIV-7 Speeds up to 512 kbit/s *KIV-7 HS Speeds up to T-1 (1.54 Mbit/s) *KIV-7HSB Speeds up to 2.048 Mbit/s *KIV-7M Speeds up to 50 Mbit/s and supports the High Assurance Internet Protocol Interoperability Specification (HAIPIS) (The National Security Agency (NSA) has established new High Assurance Internet Protocol Interoperability Specifications ( HAIPIS) that requires different vendor's Inline Network Encryption (INE) devices to be interoperable.)

Voice encryption

True voice encryption (as opposed to less secure

scrambler In telecommunications, a scrambler is a device that transposes or inverts signals or otherwise encodes a message at the sender's side to make the message unintelligible at a receiver not equipped with an appropriately set descrambling device. Wher ...

technology) was pioneered during World War II with the 50-ton

SIGSALY SIGSALY (also known as the X System, Project X, Ciphony I, and the Green Hornet) was a secure voice, secure speech system used in World War II for the highest-level Allies of World War II, Allied communications. It pioneered a number of digital co ...

, used to protect the very highest level communications. It did not become practical for widespread use until reasonable compact speech encoders became possible in the mid-1960s. The first tactical secure voice equipment was the NESTOR family, used with limited success during the Vietnam war. Other NSA voice systems include:A History of US Communications Security; the David G. Boak Lectures
National Security Agency (NSA), Volumes I, 1973, Volumes II 1981, partially released 2008, additional portions declassified October 14, 2015 * STU I and STU II — These systems were expensive and cumbersome and were generally limited to the highest levels of command *

— These telephone sets operated over ordinary telephone lines and featured the use of security tokens and

public key cryptography Public-key cryptography, or asymmetric cryptography, is the field of cryptographic systems that use pairs of related keys. Each key pair consists of a public key and a corresponding private key. Key pairs are generated with cryptographic al ...

, making them much more user friendly. They were very popular as a result. Used since the 1980s, this device is rapidly being phased out, and will no longer be supported in the near future. * 1910 Terminal — Made by a multiple of manufacturers, this device is mostly used as a secure modem. Like the STU-III, new technology has largely eclipsed this device, and it is no longer widely used. * HY-2 a vocoder for long haul circuits designed to work with the KG-13 key generator. * Secure Terminal Equipment (STE) — This system is intended to replace STU-III. It uses wide-

bandwidth Bandwidth commonly refers to: * Bandwidth (signal processing) or ''analog bandwidth'', ''frequency bandwidth'', or ''radio bandwidth'', a measure of the width of a frequency range * Bandwidth (computing), the rate of data transfer, bit rate or thr ...

voice transmitted over

ISDN Integrated Services Digital Network (ISDN) is a set of communication standards for simultaneous digital transmission of voice, video, data, and other network services over the digitalised circuits of the public switched telephone network. ...

lines. There is also a version which will communicate over a PSTN (Public Switched Telephone Network) line. It can communicate with STU-III phones and can be upgraded for FNBDT compatibility. * Sectéra Secure Module — A module that connects to the back of a commercial off the shelf cellular phone. It uses AES or SCIP for encryption. * OMNI — The OMNI terminal, made by L3 Communications, is another replacement for STU-IIIs. This device uses the FNBDT key and is used to securely send voice and data over the PSTN and ISDN communication systems. * VINSON A series of systems for tactical voice encryption including the KY-57 man portable unit and KY-58 for aircraft * HAVE QUICK and

SINCGARS Single Channel Ground and Airborne Radio System (SINCGARS) is a VHF combat network radio (CNR) used by U.S. and allied military forces. In the CNR network, the SINCGARS’ primary role is voice transmission between surface and airborne comman ...

use NSA-supplied sequence generators to provide secure

frequency hopping Frequency-hopping spread spectrum (FHSS) is a method of transmitting radio signals by rapidly changing the carrier frequency among many frequencies occupying a large spectral band. The changes are controlled by a code known to both transmitter ...

* Future Narrowband Digital Terminal (FNBDT) — Now referred to as the "Secure Communications Interoperability Protocol" ( SCIP), the FNBDT is a replacement for the wide-band STE, which uses narrow-bandwidth communications channels like

cellular telephone A mobile phone or cell phone is a portable telephone that allows users to make and receive calls over a radio frequency link while moving within a designated telephone service area, unlike fixed-location phones ( landline phones). This radio ...

circuits, rather than ISDN lines. The FNBDT/SCIP operates on the application layer of the ISO/OSI Reference Model, meaning that it can be used on top of different types of connections, regardless of the establishment method. It negotiates with the unit at the other end, much like a dial-up

modem The Democratic Movement (, ; MoDem ) is a centre to centre-right political party in France, whose main ideological trends are liberalism and Christian democracy, and that is characterised by a strong pro-Europeanist stance. MoDem was establis ...

. * Secure Iridium — NSA helped add encryption to the Iridium commercial mobile phones after it rescued the bankrupt

Iridium Iridium is a chemical element; it has the symbol Ir and atomic number 77. This very hard, brittle, silvery-white transition metal of the platinum group, is considered the second-densest naturally occurring metal (after osmium) with a density ...

. * Fishbowl — In 2012, NSA introduced an Enterprise Mobility Architecture intended to provide a secure VoIP capability using commercial grade products and an Android-based mobile phone called Fishbowl that allows classified communications over commercial wireless networks. The operational complexity of secure voice played a role in the

September 11, 2001 attacks The September 11 attacks, also known as 9/11, were four coordinated Islamist terrorist suicide attacks by al-Qaeda against the United States in 2001. Nineteen terrorists hijacked four commercial airliners, crashing the first two into ...

on the United States. According to the

9/11 Commission The National Commission on Terrorist Attacks Upon the United States, commonly known as the 9/11 Commission, was set up on November 27, 2002, to investigate all aspects of the September 11 attacks, the deadliest terrorist attack in world history ...

, an effective US response was hindered by an inability to set up a secure phone link between the National Military Command Center and the

Federal Aviation Administration The Federal Aviation Administration (FAA) is a Federal government of the United States, U.S. federal government agency within the United States Department of Transportation, U.S. Department of Transportation that regulates civil aviation in t ...

personnel who were dealing with the hijackings. ''See''

Communication during the September 11, 2001 attacks Communication problems and successes played an important role during the September 11 attacks in 2001 and their aftermath. Systems were variously destroyed or overwhelmed by loads greater than they were designed to carry, or failed to operate ...

Internet

NSA has approved a variety of devices for securing

Internet Protocol The Internet Protocol (IP) is the network layer communications protocol in the Internet protocol suite for relaying datagrams across network boundaries. Its routing function enables internetworking, and essentially establishes the Internet. IP ...

communications. These have been used to secure the Secret Internet Protocol Router Network (

), among other uses. The first commercial network layer encryption device was the Motorola Network Encryption System (NES). The system used the SP3 and KMP protocols defined by the NSA Secure Data Network System (SDNS) and were the direct precursors to IPsec. The NES was built in a three part architecture that used a small cryptographic security kernel to separate the trusted and untrusted network protocol stacks. The SDNS program defined a Message Security Protocol (MSP) that was built on the use X.509 defined certificates. The first NSA hardware built for this application was the BBN Safekeeper. The Message Security Protocol was a successor to the IETF Privacy Enhance Mail (PEM) protocol. The BBN Safekeeper provided a high degree of tamper resistance and was one of the first devices used by commercial PKI companies.

Field authentication

NSA still supports simple paper encryption and authentication systems for field use such as

DRYAD A dryad (; , sing. ) is an oak tree nymph or oak tree spirit in Greek mythology; ''Drys'' (δρῦς) means "tree", and more specifically " oak" in Greek. Today the term is often used to refer to tree nymphs in general. Types Daphnaie Thes ...

Public systems

NSA has participated in the development of several cipher devices for public use. These include: * Suite B: a set of

public key Public-key cryptography, or asymmetric cryptography, is the field of cryptographic systems that use pairs of related keys. Each key pair consists of a public key and a corresponding private key. Key pairs are generated with cryptographic alg ...

algorithm standards based on

elliptic curve cryptography Elliptic-curve cryptography (ECC) is an approach to public-key cryptography based on the algebraic structure of elliptic curves over finite fields. ECC allows smaller keys to provide equivalent security, compared to cryptosystems based on modula ...

. *

Advanced Encryption Standard The Advanced Encryption Standard (AES), also known by its original name Rijndael (), is a specification for the encryption of electronic data established by the U.S. National Institute of Standards and Technology (NIST) in 2001. AES is a variant ...

(AES): an encryption algorithm, selected by

after a public competition. In 2003, NSA certified AES for Type 1 use in some NSA-approved systems. * Secure Hash Algorithm: a widely used family of

hash algorithm A hash function is any function that can be used to map data of arbitrary size to fixed-size values, though there are some hash functions that support variable-length output. The values returned by a hash function are called ''hash values'', ...

s developed by NSA based on earlier designs by

Ron Rivest Ronald Linn Rivest (; born May 6, 1947) is an American cryptographer and computer scientist whose work has spanned the fields of algorithms and combinatorics, cryptography, machine learning, and election integrity. He is an Institute Profess ...

. *

Digital Signature Algorithm The Digital Signature Algorithm (DSA) is a Public-key cryptography, public-key cryptosystem and Federal Information Processing Standards, Federal Information Processing Standard for digital signatures, based on the mathematical concept of modular e ...

Data Encryption Standard The Data Encryption Standard (DES ) is a symmetric-key algorithm for the encryption of digital data. Although its short key length of 56 bits makes it too insecure for modern applications, it has been highly influential in the advancement of cryp ...

(DES) * Skipjack: the cipher developed for Clipper and finally published in 1998. * Clipper chip: a controversial failure that convinced NSA that it was advisable to stay out of the public arena. *

Security-Enhanced Linux Security-Enhanced Linux (SELinux) is a Linux kernel security module that provides a mechanism for supporting access control security policies, including mandatory access controls (MAC). SELinux is a set of kernel modifications and user-space to ...

: not strictly a cipher device, but a recognition that in the 21st century,

operating system An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ...

improvements are more vital to information security than better

cipher In cryptography, a cipher (or cypher) is an algorithm for performing encryption or decryption—a series of well-defined steps that can be followed as a procedure. An alternative, less common term is ''encipherment''. To encipher or encode i ...

s. * The Speck and Simon light-weight

Block cipher In cryptography, a block cipher is a deterministic algorithm that operates on fixed-length groups of bits, called ''blocks''. Block ciphers are the elementary building blocks of many cryptographic protocols. They are ubiquitous in the storage a ...

s, published in 2013.

References

Sources

NSA official site

Jerry Proc Crypto machine page

Brooke Clarke Crypto machines site

A History of U.S. Communications Security; the David G. Boak Lectures, National Security Agency (NSA), Volumes I, 1973, Volumes II 1981, partially released 2008, additional portions declassified October 14, 2015

External links

CNSS Policy No. 19, National Policy Governing the Use of High Assurance Internet Protocol Encryptor (HAIPE) Products
{{Webarchive, url=https://web.archive.org/web/20080513042825/http://www.cnss.gov/Assets/pdf/CNSSP-19.pdf , date=2008-05-13 National Security Agency *