SIGTOT

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Special paper tape reader (transmitter distributer) used with SIGTOT Onetime paper tape device used with SIGTOT cipher system aboard President Roosevelt's Douglas C-54 airplane (the 'Sacred Cow') - National Cryptologic Museum - DSC07927.JPG
Special paper tape reader (transmitter distributer) used with SIGTOT
Bell Telephone 131B2 mixer used to combine (xor) one time-tape with teleprinter signals TTY mixer 131B2 TM-11-2222 Fig 3.jpg
Bell Telephone 131B2 mixer used to combine (xor) one time-tape with teleprinter signals

SIGTOT was a one-time tape machine for encrypting teleprinter communication that was used by the United States during World War II, and after, for the most sensitive message traffic. It was developed after security flaws were discover in an earlier rotor machine for the same purpose, called SIGCUM. SIGTOT was designed by Leo Rosen and used the same Bell Telephone 132B2 mixer as SIGCUM. [1] The British developed a similar machine called the 5-UCO. Later an improved mixer, the SSM-33, replaced the 131B2, [2]

Teleprinter device for transmitting messages in written form by electrical signals

A teleprinter 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. Initially they were used in telegraphy, which developed in the late 1830s and 1840s as the first use of electrical engineering. The machines were adapted to provide a user interface to early mainframe computers and minicomputers, sending typed data to the computer and printing the response. Some models could also be used to create punched tape for data storage and to read back such tape for local printing or transmission.

Rotor machine genre of electromechanical encryption devices, used widely from the 1920s to the 1970s

In cryptography, a rotor machine is an electro-mechanical stream cipher device used for encrypting and decrypting secret messages. Rotor machines were the cryptographic state-of-the-art for a prominent period of history; they were in widespread use in the 1920s–1970s. The most famous example is the German Enigma machine, whose messages were deciphered by the Allies during World War II, producing intelligence code-named Ultra.

SIGCUM US encryption machine, in use from 1943 until the 1960s

SIGCUM, also known as Converter M-228, was a rotor cipher machine used to encrypt teleprinter traffic by the United States Army. Hastily designed by William Friedman and Frank Rowlett, the system was put into service in January 1943 before any rigorous analysis of its security had taken place. SIGCUM was subsequently discovered to be insecure by Rowlett, and was immediately withdrawn from service. The machine was redesigned to improve its security, reintroduced into service by April 1943, and remained in use until the 1960s.

The phenomenon, codenamed TEMPEST, of sensitive information leaking by way of unintended electromagnetic radiation for the circuits used inside encryption machine was first discovered coming from the 131B2 mixers used in SIGTOT. [3] :Vol I, Ch. 10

Tempest (codename) codename referring to investigations and studies of compromising emanations

TEMPEST is a U.S. National Security Agency specification and a NATO certification referring to spying on information systems through leaking emanations, including unintentional radio or electrical signals, sounds, and vibrations. TEMPEST covers both methods to spy upon others and how to shield equipment against such spying. The protection efforts are also known as emission security (EMSEC), which is a subset of communications security (COMSEC).

SIGTOT required large amounts of key tape to operate on a continual basis, which was needed for traffic flow security. In 1955, NSA produced some 1,660,000 rolls of one time tape. [3] :Vol.1, p. 42 The logistical problems involved in the generation, supply and destruction of sufficient quantities of key tape limited its use to only the most sensitive traffic. In the 1950s. the U.S. Army Security Agency began developing a replacement, an effort later taken over by the newly formed National Security Agency and resulting in the fielding of the KW-26 (ROMULUS) system. [4]

National Security Agency U.S. signals intelligence organization

The National Security Agency (NSA) is a national-level intelligence agency of the United States Department of Defense, under the authority of the Director of National Intelligence. The NSA is responsible for global monitoring, collection, and processing of information and data for foreign and domestic intelligence and counterintelligence purposes, specializing in a discipline known as signals intelligence (SIGINT). The NSA is also tasked with the protection of U.S. communications networks and information systems. The NSA relies on a variety of measures to accomplish its mission, the majority of which are clandestine.

KW-26 encryption system used by the United States Government and, later, by NATO countries

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 hours a day. It used vacuum tubes and magnetic core logic, replacing older systems, like SIGABA and the British 5-UCO, that used rotors and electromechanical relays.

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ECHELON Signals intelligence collection and analysis network

ECHELON, originally a secret government code name, is a surveillance program operated by the US with the aid of four other signatory nations to the UKUSA Security Agreement: Australia, Canada, New Zealand and the United Kingdom, also known as the Five Eyes.

One-time pad encryption technique that cannot be cracked, but requires the use of a one-time pre-shared key the same size, or longer, as the message being sent. In this technique, a plaintext is paired with a random secret key

In cryptography, the one-time pad (OTP) is an encryption technique that cannot be cracked, but requires the use of a one-time pre-shared key the same size as, or longer than, the message being sent. In this technique, a plaintext is paired with a random secret key. Then, each bit or character of the plaintext is encrypted by combining it with the corresponding bit or character from the pad using modular addition. If the key is (1) truly random, (2) at least as long as the plaintext, (3) never reused in whole or in part, and (4) kept completely secret, then the resulting ciphertext will be impossible to decrypt or break. It has also been proven that any cipher with the perfect secrecy property must use keys with effectively the same requirements as OTP keys. Digital versions of one-time pad ciphers have been used by nations for some critical diplomatic and military communication, but the problems of secure key distribution have made them impractical for most applications.

Communications security discipline of preventing unauthorized interceptors from accessing telecommunications

Communications security is the discipline of preventing unauthorized interceptors from accessing telecommunications in an intelligible form, while still delivering content to the intended recipients.

The U.S. National Security Agency (NSA) ranks cryptographic products or algorithms by a certification called product types. Product types are defined in the National Information Assurance Glossary which defines Type 1, 2, 3, and 4 products.

William F. Friedman American cryptologist

William Frederick Friedman was a US Army cryptographer who ran the research division of the Army's Signal Intelligence Service (SIS) in the 1930s, and parts of its follow-on services into the 1950s. In 1940, subordinates of his led by Frank Rowlett broke Japan's PURPLE cipher, thus disclosing Japanese diplomatic secrets before America's entrance into World War II.

The known-plaintext attack (KPA) is an attack model for cryptanalysis where the attacker has access to both the plaintext, and its encrypted version (ciphertext). These can be used to reveal further secret information such as secret keys and code books. The term "crib" originated at Bletchley Park, the British World War II decryption operation.

SIGSALY

In cryptography, SIGSALY was a secure speech system used in World War II for the highest-level Allied communications.

KL-7 off-line non-reciprocal rotor encryption machine

The TSEC/KL-7 was an off-line non-reciprocal rotor encryption machine. The KL-7 had rotors to encrypt the text, most of which moved in a complex pattern, controlled by notched rings. The non-moving rotor was in fourth from the left of the stack. The KL-7 with 12 rotors also encrypted the message indicator and was code named ADONIS.

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 have become known and its most modern systems share at least some features with commercial products.

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. The model number is due to its storage capacity — 64 kibibits, enough to store multiple encryption keys. Most frequently it was used in key-splitting applications: either the encryption device or the KSD-64 alone is worthless, but together they can be used to make encrypted connections. It was also used alone as a fill device for transfer of key material, as for the initial seed key loading of an STU-III secure phone.

Glossary of cryptographic keys

This glossary lists types of keys as the term is used in cryptography, as opposed to door locks. Terms that are primarily used by the U.S. National Security Agency are marked (NSA). For classification of keys according to their usage see cryptographic key types.

The 5-UCO was an on-line one-time tape Vernam cipher encryption system developed by the UK during World War II for use on teleprinter circuits. During the 1950s, it was used by the UK and US for liaison on cryptanalysis.

Sanitization is the process of removing sensitive information from a document or other message, so that the document may be distributed to a broader audience. When the intent is secrecy protection, such as in dealing with classified information, sanitization attempts to reduce the document's classification level, possibly yielding an unclassified document. When the intent is privacy protection, it is often called data anonymization. Originally, the term sanitization was applied to printed documents; it has since been extended to apply to computer media and the problem of data remanence as well.

Fill device module used to load cryptographic keys into electronic encryption machines

A fill device or key loader is a module used to load cryptographic keys into electronic encryption machines. Fill devices are usually hand held and electronic ones are battery operated.

Bullrun (decryption program) code name of a decryption program run by the NSA

Bullrun is a clandestine, highly classified program to crack encryption of online communications and data, which is run by the United States National Security Agency (NSA). The British Government Communications Headquarters (GCHQ) has a similar program codenamed Edgehill. According to the BULLRUN classification guide published by The Guardian, the program uses multiple methods including computer network exploitation, interdiction, industry relationships, collaboration with other intelligence community entities, and advanced mathematical techniques.

NESTOR (encryption) Family of wideband secure voice systems

NESTOR was a family of compatible, tactical, wideband secure voice systems developed by the U.S. National Security Agency and widely deployed during the Vietnam War. NESTOR consists of three systems. The KY-8 was used in vehicular and afloat applications; the KY-28 was the airborne version: and the KY-38 was the portable or man-pack model. About 30,000 NESTOR equipments were produced prior to their replacement by the VINSON secure voice family.

References

  1. ↑ "131B2 Manual TM-11-2209" (PDF).
  2. ↑ SSM-33 (SIGTOT) Cryptosystem
  3. 1 2 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
  4. ↑ Melville Klein, "Securing Record Communications: The TSEC/KW-26", 2003, NSA brochure, p. 4,
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