The National Security Agency took over responsibility for all U.S. Government encryption systems when it was formed in 1952. The technical details of most NSA-approved systems are still classified, but much more about its early systems has become known and its most modern systems share at least some features with commercial products. The National Security Agency/Central Security Service (NSA/CSS) is the U.S. governments cryptologic organization. ... ... // In cryptography, encryption is the process of obscuring information to make it unreadable without special knowledge. ... 1952 (MCMLII) was a Leap year starting on Tuesday (link will take you to calendar). ... An example of a U.S. classified document; page 13 of a U.S. National Security Agency report [1] on the USS Liberty incident, partially declassified and released to the public in July 2003. ...

One thing one can say about NSA encryption systems is that their outward appearance becomes less interesting as time goes on. Rotor machines from the 1940s and 1950s were mechanical marvels. The first generation electronic systems were quirky devices with cantankerous punch card readers for loading keys and failure-prone, tricky-to-maintain vacuum tube circuitry. More recent systems are just black boxes, often literally. In fact they are called blackers in NSA parlance because they convert classified signals (red) into unclassified signals (black). They typically have electrical connectors 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 including keys and perhaps the encryption algorithms. In cryptography, a rotor machine is a electro-mechanical device used for encrypting and decrypting secret messages. ... Punched cards (or Hollerith cards, or IBM cards), are pieces of stiff paper that contain digital information represented by the presence or absence of holes in predefined positions. ... A key is a piece of information that controls the operation of a cryptography algorithm. ... In electronics, a vacuum tube (U.S. and Canadian English) or (thermionic) valve (outside North America) is a device generally used to amplify, or otherwise modify, a signal by controlling the movement of electrons in an evacuated space. ... Black box is technical jargon for a device or system or object when it is viewed primarily in terms of its input and output characteristics. ... An electrical connector is a device for joining electrical circuits together. ... In cryptography, zeroisation (also spelled zeroization) is the practice of erasing sensitive parameters (especially keys) from a cryptographic module to prevent their disclosure if the equipment is captured. ...

Security factors

NSA has to deal with many factors in ensuring the security of communication and information (COMSEC and INFOSEC in NSA jargon): Communications security (COMSEC): Measures and controls taken to deny unauthorized persons information derived from telecommunications and ensure the authenticity of such telecommunications. ... Information security deals with several different trust aspects of information. ...

• Confidentiality and authenticity - making sure messages cannot be read by unauthorized people and that they cannot be forged (nonrepudiation). Little is publicly known about the algorithms NSA has developed for protecting classified information, what NSA calls Type 1 algorithms. 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.
• Traffic flow security - making sure an adversary cannot obtain information from traffic analysis, often accomplished by link encryption.
• Key management - getting keys securely to thousands of crypto boxes in the field, perhaps the most challenging part of any encryption system. One NSA goal is benign fill (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 U.S. 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 plaintext from compromise by electronic, acoustic or other emanations.
• Tamper proof, tamper evident, self destruct - ensuring security even if encryption systems are physically accessed without authorization or are captured.
• Meeting military specifications for size, weight, power consumption, MTBF and ruggedness to fit in mobile platforms.
• EMP hardening - protecting against nuclear explosion effects, particularly electromagnetic pulse.
• Ensuring compatibility with military and commercial communication standards.
• 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 NATO, allied and coalition forces without compromising secret methods.

Non-repudiation is the concept of ensuring that a contract, especially one agreed to via the Internet, cannot later be denied by one of the parties involved. ... An example of a U.S. classified document; page 13 of a U.S. National Security Agency report [1] on the USS Liberty incident, partially declassified and released to the public in July 2003. ... In cryptography, a Type 1 product is a device or system certified by the National Security Agency (NSA) for use in cryptographically securing classified U.S. Government information. ... 2003 (MMIII) was a common year starting on Wednesday of the Gregorian calendar. ... In cryptography, Skipjack is a block cipher — an algorithm for encryption — developed by the US National Security Agency (NSA). ... In cryptography, the Advanced Encryption Standard (AES), also known as Rijndael, is a block cipher adopted as an encryption standard by the U.S. government. ... Traffic analysis is the process of intercepting and examining messages in order to deduce information from patterns in communication. ... Link encryption is an approach to communications security that encrypts and decrypts all traffic at each end a communications line (e. ... In cryptography, key management includes all of the provisions made in a cryptosystem design, in cryptographic protocols in that design, in user procedures, and so on, which are related to generation, exchange, storage, safeguarding, use, vetting, and replacement of keys. ... The Clipper chip is a chipset that was developed and promoted by the U.S. Government as an encryption device to be adopted by telecommunications companies for voice transmission. ... Key escrow is an arrangement in which the keys needed to decrypt encrypted data are held in escrow by a third party, so that someone else (typically government agencies) can obtain them to decrypt messages which they suspect to be relevant to national security. ... A tempest is a violent storm. ... The plain text term has a different meaning. ... In engineering and telecommunication, the mean time between failures (MTBF) is the average time a system will operate without a failure. ... It has been suggested that Nuclear explosive be merged into this article or section. ... Example of an electromagnetic pulse, in this case caused by the electrical discharge required to fire the Z machine. ...

Five generations of NSA encryption

The large number of encryption systems 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 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) at midnight, GMT. The highest level traffic was sent using one time tape systems, including the British 5-UCO, that required vast amounts of paper tape keying material. The 1950s was the decade spanning from the 1st of January, 1950 to the 31st December, 1959. ... Combatants Major Allied powers: United Kingdom Soviet Union United States Republic of China and others Major Axis powers: Nazi Germany Italy Japan and others Commanders Winston Churchill Joseph Stalin Franklin Roosevelt Harry Truman Chiang Kai-Shek Adolf Hitler Benito Mussolini Hideki Tojo Casualties Military dead: 17,000,000 Civilian dead... SIGABA In the history of cryptography, the ECM Mark II was a rotor machine used by the United States from World War II (WWII) until the 1950s. ... KL-7 on display at USAF Communications Agency museum. ... For alternate meanings of GMT, see GMT (disambiguation). ... The 5-UCO was a one time tape (OTT) Vernam cipher encryption system developed by the U.K. during World War II for use on teletype circuits. ...

Second generation-vacuum tubes

Second generation systems (1970s) were all electronic designs based on vacuum tubes and transformer logic. Algorithms appear to be based on linear feedback shift registers, perhaps with some non-linear elements thrown in to make them more difficult to cryptanalyze. Keys were loaded by placing a punch card in a locked reader on the front panel. 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. The 1970s decade refers to the years from 1970 to 1979, inclusive. ... In electronics, a vacuum tube (U.S. and Canadian English) or (thermionic) valve (outside North America) is a device generally used to amplify, or otherwise modify, a signal by controlling the movement of electrons in an evacuated space. ... A linear feedback shift register (LFSR) is a shift register whose input bit is a linear function of its previous state. ... Punched cards (or Hollerith cards, or IBM cards), are pieces of stiff paper that contain digital information represented by the presence or absence of holes in predefined positions. ... John Anthony Walker Junior, born July 28, 1937, was a Chief Warrant Officer and communications specialist for the U.S. Navy, who sold his services as a spy to the Soviet Union from 1967 to 1985, the height of the Cold War era. ...

Third generation-integrated circuits

Third generation systems (1980s) were transistorized and based on integrated circuits 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 box 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 paper tape 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. The 1980s refers to the years of 1980 to 1989. ... Integrated circuit showing memory blocks, logic and input/output pads around the periphery A monolithic integrated circuit (also known as IC, microchip, silicon chip, computer chip or chip) is a miniaturized electronic circuit (consisting mainly of semiconductor devices, as well as passive components) that has been manufactured in the surface... A KOI-18 on display at the National Cryptologic Museum. ... KY-57 voice encryptor. ... KYK-13 on display at the National Cryptologic Museum. ...

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 tokens, 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 only have to call a special phone number once a year to have their encryption updated. Public key methods (FIREFLY) were introduced for electronic key management (EKMS). Keys can 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, IP (originally developed by DOD's ARPA), and optical fiber multiplexing. Classified networks, such as SIPRNet (Secret Internet Protocol Router Network) and JWICS (Joint Worldwide Intelligence Communications System), were built using commercial Internet 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 Internet. The examples and perspective in this article or section may not represent a worldwide view. ... Several types of security tokens. ... The KSD-64[A] Crypto Ignition Key (CIK) is an NSA-developed EEPROM chip packed in a plastic case that looks like a toy key. ... Fortezza is also a town in Italy, see: Franzensfeste-Fortezza A Fortezza card made by Mykotronx Corp. ... The Clipper chip is a chipset that was developed and promoted by the U.S. Government as an encryption device to be adopted by telecommunications companies for voice transmission. ... A STU-III secure telephone; this model AT&T STU-III is a family of secure telephones introduced in 1987 by the NSA for use by the United States government, its contractors, and its allies . ... Genera Curtos Cyphonocerus Drilaster Ellychnia Hotaria Lampyris Lucidina Lucidota Luciola - Japanese fireflies Phausis Photinus - common eastern firefly Photuris Pristolycus Pyractomena Pyrocoelia Stenocladius many others Wikispecies has information related to: Lampyridae Fireflies (family Lampyridae), also called lightning bugs, are luminous beetles. ... The Electronic Key Management System (EKMS) system is an National Security Agency led program responsible for Communications Security (COMSEC) key management, accounting and distribution. ... AN/CYZ-10 The AN/CYZ-10, or Data Transfer Device (DTD) is an NSA-developed, portable, hand-held device capable of securely receiving, storing, and transferring data between compatible cryptographic and communications equipment. ... Ethernet is a large and diverse family of frame-based computer networking technologies for local area networks (LANs). ... The Internet Protocol (IP) is a data-oriented protocol used for communicating data across a packet-switched internetwork. ... The acronym ARPA has several meanings: It is the former abbreviation of a U.S. military organization now known as the Defense Advanced Research Projects Agency (DARPA). ... The SIPRNet (Secret [formerly Secure] Internet Protocol Router Network) is a system of interconnected computer networks used by the U.S. Department of Defense to transmit classified information (up to and including information classified SECRET//NOFORN) by packet switching over the TCP/IP protocols in a completely secure environment. ... The Joint Worldwide Intelligence Communications System (JWICS) is a secure network designed to meet the multimedia requirements of the DOD intelligence community. ...

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 challenging aspect. NSA's role will increasingly be to provide guidance to commercial firms designing systems for government use. Other agencies, particularly NIST, have taken on the role of supporting security for commercial and sensitive but unclassified applications. NSA's certification of the NIST-selected AES algorithm for classified use "in NSA approved systems" suggests the future path. As a non-regulatory agency of the United States Department of Commerce’s Technology Administration, the National Institute of Standards (NIST) develops and promotes measurement, standards, and technology to enhance productivity, facilitate trade, and improve the quality of life. ... In cryptography, the Advanced Encryption Standard (AES), also known as Rijndael, is a block cipher adopted as an encryption standard by the U.S. government. ...

NSA has helped develop two major standards for secure communication: the Future Narrow Band Digital Terminal (FNBDT) for voice communications and High Assurance Internet Protocol Interoperability Standard (HAIPIS) for computer networking. FNBDT is the U.S. Governments new standard for secure voice communication. ... A HAIPE (High Assurance Internet Protocol Encryptor) is a Type 1 encryption device that complies with the National Security Agencys HAIPE IS (formerly the HAIPIS, the High Assurance Internet Protocol Interoperability Specification). ...

NSA encryption by type of application

The large number of encryption systems that NSA has developed can be grouped by application:

Record traffic encryption

During World War II, written messages (known as record traffic) were encrypted off line on special, and highly secret, rotor machines and then transmitted in five letter code groups using Morse code or teletype circuits, to be decrypted off-line by similar machines 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. Combatants Major Allied powers: United Kingdom Soviet Union United States Republic of China and others Major Axis powers: Nazi Germany Italy Japan and others Commanders Winston Churchill Joseph Stalin Franklin Roosevelt Harry Truman Chiang Kai-Shek Adolf Hitler Benito Mussolini Hideki Tojo Casualties Military dead: 17,000,000 Civilian dead... In cryptography, a rotor machine is a electro-mechanical device used for encrypting and decrypting secret messages. ... 1922 Chart of the Morse Code Letters and Numerals Morse code is a method for transmitting information, using standardized sequences of short and long marks or pulses — commonly known as dots and dashes — for the letters, numerals, punctuation and special characters of a message. ... A teleprinter (teletypewriter, teletype or TTY) is a now largely obsolete electro-mechanical typewriter which can be used to communicate typed messages from point to point through a simple electrical communications channel, often just a pair of wires. ... SIGABA In the history of cryptography, the ECM Mark II was a rotor machine used by the United States from World War II (WWII) until the 1950s. ... KL-7 on display at USAF Communications Agency museum. ...

The KW-26 ROMULUS was a second generation encryption system in wide use that could be inserted into teletype circuits so traffic was encrypted and decrypted automatically. It used electronic shift registers 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. An array of KW-26s The TSEC/KW-26, code named ROMULUS, was an encryption system used by the U.S. Government and, later, by NATO countries. ... A linear feedback shift register (LFSR) is a shift register whose input bit is a linear function of its previous state. ... The 1980s refers to the years of 1980 to 1989. ... KG-84A and KG-84C. US Navy photo. ...

Fleet broadcast

U.S. Navy ships traditionally avoid using their radios to prevent adversaries from locating them by direction finding. 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 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. Direction finding (DF) refers to the establishment of the direction from which a received signal was transmitted. ... Call sign can refer to different types of call signs: Airline call sign Aviator call sign Cosmonaut call sign Radio and television call signs Tactical call sign, also known as a tactical designator See also: International Callsign Allocations, Maritime Mobile Service Identity This is a disambiguation page — a navigational... SIGABA In the history of cryptography, the ECM Mark II was a rotor machine used by the United States from World War II (WWII) until the 1950s. ... KL-7 on display at USAF Communications Agency museum. ...

The second generation KW-37 automated monitoring of the fleet broadcast by connecting in line between the radio receiver and a teleprinter. It, in turn, was replaced by the more compact and reliable third generation KW-46. The KW-37, code named JASON, was an encryption system developed In the 1950s by the U.S. National Security Agency to protect fleet broadcasts of the U.S. Navy. ... Teletype machines in World War II A teleprinter (teletypewriter, teletype or TTY) is a now largely obsolete electro-mechanical typewriter which can be used to communicate typed messages from point to point through a simple electrical communications channel, often just a pair of wires. ...

Strategic forces

NSA has no graver responsibility than protecting the command and control systems for nuclear forces. The KG-3X series is used in the U.S. 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 U.S. strategic forces. The Navy is replacing the KG-38 used in nuclear submarines with KOV-17 circuit modules incorporated in new long-wave receivers, based on commercial VME packaging. In 2004, the U.S. 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. USS Los Angeles A submarine is a specialized watercraft that can operate underwater. ... This article is about the operating system. ... 2004 (MMIV) was a leap year starting on Thursday of the Gregorian calendar. ...

Trunk encryption

Modern communication systems multiplex many signals into wideband data streams that are transmitted over optical fiber, coaxial cable, microwave relay, and communication satellites. These wide-band circuits require very fast encryption systems. In telecommunications, multiplexing (also muxing or MUXing) is the combining of two or more information channels onto a common transmission medium using hardware called a multiplexer or (MUX). ... A bundle of optical fibers. ... Coaxial cable is an electrical cable consisting of a round conducting wire, surrounded by an insulating spacer, surrounded by a cylindrical conducting sheath, usually surrounded by a final insulating layer. ... Microwaves are electromagnetic waves with wavelengths longer than those of terahertz (THz) wavelengths, but relatively short for radio waves. ... U.S. military MILSTAR communications satellite A communications satellite (sometimes abbreviated to comsat) is an artificial satellite stationed in space for the purposes of telecommunications using radio at microwave frequencies. ...

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 optical standards up to 2.5 Gbit/s. Digital signal 1 (DS1, also known as a T1) is a T-carrier signaling scheme devised by Bell Labs. ... Synchronous Optical Networking, commonly known as SONET, is a standard for communicating digital information over optical fiber. ...

Voice encryption

KY-68 tactical secure telephone.

True voice encryption (as opposed to less secure scrambler technology) was pioneered during World War II with the 50-ton SIGSALY, used to protect the very highest level communications. It did not become practical for wide spread use until reasonable compact speech encoders became possible in the 1970s. Image File history File links Download high-resolution version (780x778, 226 KB) w:KY-68 voice encryption system on on display at the w:National Cryptologic Museum in 2005. ... Image File history File links Download high-resolution version (780x778, 226 KB) w:KY-68 voice encryption system on on display at the w:National Cryptologic Museum in 2005. ... In telecommunications, a scrambler is a device that transposes or inverts signals or otherwise encodes a message at the transmitter to make the message unintelligible at a receiver not equipped with an appropriately set descrambling device. ... SIGSALY exhibit at the National Cryptologic Museum In cryptography, SIGSALY (also Green Hornet) was a telephone scrambler used in World War II for the highest-level Allied communications. ... Speech coding is the compression of speech (into a code) for transmission with speech codecs that use audio signal processing and speech processing techniques. ... 1970 (MCMLXX) was a common year starting on Thursday (the link is to a full 1970 calendar). ...

• STU I and STU II - These systems were expensive and cumbersome and were generally limited to the highest levels of command
• STU-III - These telephone sets operated over ordinary telephone lines and featured the use of security tokens and public key cryptography, making them much more user friendly. They were very popular as a result. Used since the 1980's, 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.
• Secure Terminal Equipment (STE) - This system is intended to replace STU-III. It uses wide-bandwidth voice transmitted over ISDN lines. It can communicate with STU-III phones and can be upgraded for FNBDT compatibility.
• GSM Secure module - The a secure cellular phone module that connects to the back of a commercial off the shelf cellular phone. It uses an FNBDT key for encryption.
• OMNI - The OMNI terminal, made by L3 Communications, is another replacement for STU-III's. This device uses the FNBDT key and is used to securely send voice and data over the PSTN and ISDN communication systems.
• secure Iridium - The US Government got a real bargain when it rescued the bankrupt Iridium commercial mobile phone venture. NSA helped add encryption to the Iridium phones.
• KY-57 (VINSON) - One of a series of systems for tactical voice encryption
• HAVE QUICK and SINCGARS use NSA-supplied sequence generators to provide secure frequency hopping
• FNBDT - The US Government may have zigged when it should have zagged in selecting wide-band voice for STE. The cell phone phenomenon exploded shortly thereafter. Cell phone are narrow band devices, so a new strategy was needed. FNBDT operates on the application layer of the ISO/OSI Reference Model. That means it does not care how the phone call was established. It negotiates with the unit at the other end, much like V.90 dial-up modems.

The operational complexity of secure voice played a role in the September 11, 2001 attacks on the United States. According to the 911 Commission, an effective U.S. response was hindered by an inability to set up a secure phone link between the National Military Command Center and the Federal Aviation Administration personnel who were dealing with the hijackings. See Communication during the September 11, 2001 attacks. STU-I secure telephone desk set. ... STU-II secure telephone The STU-II is a secure telephone developed by the U.S. National Security Agency. ... A STU-III secure telephone; this model AT&T STU-III is a family of secure telephones introduced in 1987 by the NSA for use by the United States government, its contractors, and its allies . ... Public key cryptography is a form of cryptography which generally allows users to communicate securely without having prior access to a shared secret key, by using a pair of cryptographic keys, designated as public key and private key, which are related mathematically. ... STE desk set. ... This article or section does not cite its references or sources. ... ISDN is also short for isosorbide dinitrate Integrated Services Digital Network (ISDN) is a type of circuit switched telephone network system, designed to allow digital (as opposed to analog) transmission of voice and data over ordinary telephone copper wires, resulting in better quality and higher speeds, than available with analog... The Omni adds Type 1 secure voice and secure data to any standard analog telephone or modem connected computer. ... An Iridium phone (without the aerial) The Iridium satellite constellation is a system of 66 active communication satellites and spares around the Earth. ... The Speech Security Equipment (VINSON), TSEC/KY-57, is a portable, tactical cryptographic device in the VINSON family, designed to provide voice encryption for a range of military communication devices such as radio or telephone. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... SINCGARS stands for Single Channel Ground and Airborne Radio System. ... Frequency-hopping spread spectrum (FHSS) is a spread-spectrum method of transmitting signals by rapidly switching a carrier among many frequency channels, using a pseudorandom sequence known to both transmitter and receiver. ... FNBDT is the U.S. Governments new standard for secure voice communication. ... Motorola T2288 mobile phone A mobile phone is a portable electronic device which behaves as a normal telephone whilst being able to move over a wide area (compare cordless phone which acts as a telephone only within a limited range). ... FNBDT is the U.S. Governments new standard for secure voice communication. ... The Open Systems Interconnection Reference Model (OSI Model or OSI Reference Model for short) is a layered abstract description for communications and computer network protocol design, developed as part of the Open Systems Interconnect initiative. ... V.90 is an ITU-T recommendation for a modem, allowing 56 kbit/s download and 33. ... A modem (from modulate and demodulate) is a device that modulates an analogue carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. ... A sequential look at United Flight 175 crashing into the south tower of the World Trade Center The September 11, 2001 attacks (often referred to as 9/11—pronounced nine eleven or nine one one) consisted of a series of coordinated terrorist[1] suicide attacks upon the United States, predominantly... The National Commission on Terrorist Attacks Upon the United States, also known as the 9/11 Commission, was set up in late 2002 to prepare a full and complete account of the circumstances surrounding the September 11, 2001 attacks including preparedness for and the immediate response to the attacks. ...   FAA redirects here. ... Communications problems and successes played an important role in the September 11, 2001 attacks and their aftermath. ...

Internet

NSA has approved a variety of devices for securing Internet protocol communications. These have been used to secure SIPRNet, the Secret Internet Protocol Router Network, among other uses. The Internet Protocol (IP) is a data-oriented protocol used for communicating data across a packet-switched internetwork. ... The SIPRNet (Secret [formerly Secure] Internet Protocol Router Network) is a system of interconnected computer networks used by the U.S. Department of Defense to transmit classified information (up to and including information classified SECRET//NOFORN) by packet switching over the TCP/IP protocols in a completely secure environment. ...

Field authentication

NSA still supports simple paper encryption and authentication systems for field use such as DRYAD. The Dryad by Evelyn De Morgan Dryads are female tree spirits in Greek mythology. ...

Public systems

NSA has participated in the development of several encryption systems for public use. These include:

• Suite B - a set of public key algorithm standards based on elliptic curve cryptography.
• Advanced Encryption Standard (AES) - a Belgian-designed encryption algorithm, selected by NIST 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 algorithms developed by NSA based on earlier designs by Ron Rivest.
• Digital Signature Algorithm
• Data Encryption Standard (DES) - NSA's degree of involvement in DES is disputed.
• Skipjack - the cipher developed for Clipper and finally published in 1998.
• Clipper chip - a controversial failure that convinced NSA to stay out of the public arena.
• Security-Enhanced Linux - not strictly an encryption system, but a recognition that in the 21st century, operating system improvements are more vital to information security than better ciphers.

Suite B is a set of public key cryptography algorithms based on elliptic curve cryptography promulgated by the US National Security Agency as part of a US Government standard for securing sensitive-but-unclassified (SBU) information. ... Public key cryptography is a form of cryptography which generally allows users to communicate securely without having prior access to a shared secret key, by using a pair of cryptographic keys, designated as public key and private key, which are related mathematically. ... Elliptic curve cryptography (ECC) is an approach to public-key cryptography based on the algebraic structure of elliptic curves over finite fields. ... In cryptography, the Advanced Encryption Standard (AES), also known as Rijndael, is a block cipher adopted as an encryption standard by the U.S. government. ... As a non-regulatory agency of the United States Department of Commerce’s Technology Administration, the National Institute of Standards (NIST) develops and promotes measurement, standards, and technology to enhance productivity, facilitate trade, and improve the quality of life. ... 2003 (MMIII) was a common year starting on Wednesday of the Gregorian calendar. ... In cryptography, a Type 1 product is a device or system certified by the National Security Agency (NSA) for use in cryptographically securing classified U.S. Government information. ... The SHA (Secure Hash Algorithm) family is a set of related cryptographic hash functions designed by the National Security Agency (NSA) and published by the National Institute of Standards and Technology (NIST). ... In cryptography, a cryptographic hash function is a hash function with certain additional security properties to make it suitable for use as a primitive in various information security applications, such as authentication and message integrity. ... Professor Ron Rivest Professor Ronald Linn Rivest (born 1947, Schenectady, New York) is a cryptographer, and is the Andrew and Erna Viterbi Professor of Computer Science at MITs Department of Electrical Engineering and Computer Science. ... The Digital Signature Algorithm (DSA) is a United States Federal Government standard or FIPS for digital signatures. ... The Data Encryption Standard (DES) is a cipher (a method for encrypting information) selected as an official Federal Information Processing Standard (FIPS) for the United States in 1976, and which has subsequently enjoyed widespread use internationally. ... In cryptography, Skipjack is a block cipher — an algorithm for encryption — developed by the US National Security Agency (NSA). ... 1998 (MCMXCVIII) was a common year starting on Thursday of the Gregorian calendar, and was designated the International Year of the Ocean. ... The Clipper chip is a chipset that was developed and promoted by the U.S. Government as an encryption device to be adopted by telecommunications companies for voice transmission. ... Security-Enhanced Linux (SELinux) is an implementation of mandatory access control using Linux Security Modules (LSM) in the Linux kernel, based on the principle of least privilege. ... An operating system (OS) is a computer program that manages the hardware and software resources of a computer. ... This article is about algorithms for encryption and decryption. ...

External links

• NSA official site
• Jerry Proc Crypto machine page
• Brooke Clarke Crypto machines site