Communications intelligence: Difference between revisions
imported>Howard C. Berkowitz (fixed link error) |
mNo edit summary |
||
(6 intermediate revisions by 5 users not shown) | |||
Line 1: | Line 1: | ||
{{subpages}} | {{PropDel}}<br><br>{{subpages}} | ||
'''Communications Intelligence''' (COMINT) is the subset of SIGINT concerned with signals intended to be intelligible to human beings, in the form of voice, messages, or images. The US Joint Chiefs of Staff defines it as "Technical information and intelligence derived from foreign communications by other than the intended recipients".<ref name=JP1-02>{{citation | {{TOC|right}} | ||
'''Communications Intelligence''' (COMINT) is the subset of [[signals intelligence|SIGINT]] concerned with signals intended to be intelligible to human beings, in the form of voice, messages, or images. The US Joint Chiefs of Staff defines it as "Technical information and intelligence derived from foreign communications by other than the intended recipients".<ref name=JP1-02>{{citation | |||
| last = US Department of Defense | | last = US Department of Defense | ||
| authorlink = U.S. Department of Defense | | authorlink = U.S. Department of Defense | ||
Line 8: | Line 9: | ||
}}</ref> | }}</ref> | ||
Unfortunately, the terms SIGINT and COMINT often are interchanged, with the additional confusion, in U.S. practice, that all SIGINT designated as [[sensitive compartmented intelligence]] (SCI) is in what is called the "COMINT Control System". Both COMINT and ELINT SCI are stamped with the control marking '''Handle through COMINT Channels Only (CCO)''' It should be noted that COMINT is commonly referred to as SIGINT, which can cause confusion when talking about the broader intelligence disciplines. | Unfortunately, the terms SIGINT and COMINT often are interchanged, with the additional confusion, in U.S. practice, that all SIGINT designated as [[compartmented control system|sensitive compartmented intelligence]] (SCI) is in what is called the "COMINT Control System". Both COMINT and ELINT SCI are stamped with the control marking '''Handle through COMINT Channels Only (CCO)''' It should be noted that COMINT is commonly referred to as SIGINT, which can cause confusion when talking about the broader intelligence disciplines. | ||
Information among people, or from sensors (e.g., video) will reveal some or all of the following: | Information among people, or from sensors (e.g., video) will reveal some or all of the following: | ||
Line 19: | Line 20: | ||
==Cryptanalysis== | ==Cryptanalysis== | ||
While SIGINT and COMINT are usually assumed to involve electromagnetic signals, encrypted text, in the form of printer or facsimile output, may be | While SIGINT and COMINT are usually assumed to involve electromagnetic signals, encrypted text, in the form of printer or facsimile output, may be captured. Of course, it would be most common to intercept text or encrypted voice sent by radio, or on cables that are tapped. In any case, the discipline of [[cryptanalysis]] is generally not dependent on the means of signal transmission. The general techniques of mathematical cryptanalysis are extremely complex, and are discussed in separate articles. | ||
Modern cryptosystems use precision time-of-day as another variable, so in addition to recording the signals | Modern cryptosystems use precision time-of-day as another variable, so in addition to recording the signals of extracted (but encrypted) information, the recorders must have synchronized timestamps. GPS is the usual source of precision timing for Western forces. | ||
===Acoustic cryptanalysis=== | ===Acoustic cryptanalysis=== | ||
Line 42: | Line 43: | ||
In the Second World War, the United States used volunteer communicators known as [[code talkers]], who used languages such as [[Navajo]], [[Comanche]] and [[Choctaw]], which would be understood by few people, even in the U.S., who did not grow up speaking the language. Even within these uncommon languages, the code talkers used specialized codes, so a "butterfly" might be a specific Japanese aircraft. British forces made more limited use of [[Welsh language|Welsh]] speakers for the additional protection. | In the Second World War, the United States used volunteer communicators known as [[code talkers]], who used languages such as [[Navajo]], [[Comanche]] and [[Choctaw]], which would be understood by few people, even in the U.S., who did not grow up speaking the language. Even within these uncommon languages, the code talkers used specialized codes, so a "butterfly" might be a specific Japanese aircraft. British forces made more limited use of [[Welsh language|Welsh]] speakers for the additional protection. | ||
While modern electronic encryption does away with the need for armies to use obscure languages, it is certainly possible that | While modern electronic encryption does away with the need for armies to use obscure languages, it is certainly possible that guerrilla groups might use rare dialects that few outside their ethnic group would understand. | ||
==Signal acquisition== | ==Signal acquisition== | ||
Line 92: | Line 93: | ||
In WWII, for example, the Japanese Navy made possible the interception and death of the Combined Fleet commander, Admiral [[Isoroku Yamamoto]], by BEADWINDOW 5 and 7 violations. They identified a key person's movement over a low-security cryptosystem. | In WWII, for example, the Japanese Navy made possible the interception and death of the Combined Fleet commander, Admiral [[Isoroku Yamamoto]], by BEADWINDOW 5 and 7 violations. They identified a key person's movement over a low-security cryptosystem. | ||
==References== | ==References== | ||
{{reflist|2}} | {{reflist|2}}[[Category:Suggestion Bot Tag]] |
Latest revision as of 07:01, 31 July 2024
This article may be deleted soon. | ||
---|---|---|
Communications Intelligence (COMINT) is the subset of SIGINT concerned with signals intended to be intelligible to human beings, in the form of voice, messages, or images. The US Joint Chiefs of Staff defines it as "Technical information and intelligence derived from foreign communications by other than the intended recipients".[1] Unfortunately, the terms SIGINT and COMINT often are interchanged, with the additional confusion, in U.S. practice, that all SIGINT designated as sensitive compartmented intelligence (SCI) is in what is called the "COMINT Control System". Both COMINT and ELINT SCI are stamped with the control marking Handle through COMINT Channels Only (CCO) It should be noted that COMINT is commonly referred to as SIGINT, which can cause confusion when talking about the broader intelligence disciplines. Information among people, or from sensors (e.g., video) will reveal some or all of the following:
CryptanalysisWhile SIGINT and COMINT are usually assumed to involve electromagnetic signals, encrypted text, in the form of printer or facsimile output, may be captured. Of course, it would be most common to intercept text or encrypted voice sent by radio, or on cables that are tapped. In any case, the discipline of cryptanalysis is generally not dependent on the means of signal transmission. The general techniques of mathematical cryptanalysis are extremely complex, and are discussed in separate articles. Modern cryptosystems use precision time-of-day as another variable, so in addition to recording the signals of extracted (but encrypted) information, the recorders must have synchronized timestamps. GPS is the usual source of precision timing for Western forces. Acoustic cryptanalysisOne special case, where signal and human interface are known, is called acoustic cryptanalysis, where it is possible to record both the sounds of the human input (e.g., strokes on a keyboard) or output (e.g., the sounds of an impact printer), and correlate the two. This was first done when the encryption and decryption were done with electromechanical devices. In 1956, U.K. COMINT specialists succeeded in such an attack against Hagelin machines used by Egypt. The technique was assigned the code word "ENGULF".[2] A defense against such attacks, even with all-electronic workstations and cryptosystems, can involve generating random noise that corresponds to combinations of keystrokes.[3] One of the reasons to do acoustic cryptanalysis is not to break all encryption with this technique, but to gain insight into the way the cryptosystem operates on words or messages that the cryptanalyst can assume will be sent. This is called a known plaintext attack The threat of new code talkersIn the Second World War, the United States used volunteer communicators known as code talkers, who used languages such as Navajo, Comanche and Choctaw, which would be understood by few people, even in the U.S., who did not grow up speaking the language. Even within these uncommon languages, the code talkers used specialized codes, so a "butterfly" might be a specific Japanese aircraft. British forces made more limited use of Welsh speakers for the additional protection. While modern electronic encryption does away with the need for armies to use obscure languages, it is certainly possible that guerrilla groups might use rare dialects that few outside their ethnic group would understand. Signal acquisitionEven if a radio signal is not encrypted, there are a variety of electronic characteristics that must be solved before the human-sensible information can be extracted. Given the simplifying assumption that the signal stays on a single frequency, it will still be necessary to determine the type of modulation in use. In a field environment, locating, capturing, and extracting meaningful information, even if the information is encryption, may require a team of analysts, substantial automation, or both. Remember that in other than the simplest situations, there are apt to be multiple signals of interest, which each may need more than one instrument and analyst. For example, the Israel Aerospace Industries ELK-7035 commercial COMINT system,[4] intended for multiple signal interception, has features including:
Voice interceptionA basic COMINT technique is to listen for voice communications, usually over radio but possibly "leaking" from telephones or from wiretaps. If the voice is encrypted, the encryption must be solved. Even if the voice is not encrypted but is digitized, the encoding must be recognized before the voice can be understood. Obviously, the interceptor must understand the language being spoken. Finding linguists, especially those that will understand unusual dialects, is one of the practical challenges for COMINT organizations. Text interceptionNot all communication is in voice. Morse code interception was once very important, but Morse code telegraphy is now obsolescent in the western world, although possibly used by special operations forces. Such forces, however, now have portable cryptographic equipment. Morse code is still used by military forces of former Soviet Union countries. Specialists scan radio frequencies for character sequences (e.g., electronic mail) and facsimile. Signaling channel interceptionA given digital communications link can carry thousands or millions of voice communications, especially in developed countries. Without addressing the legality of such actions, the problem of identifying which channel contains which conversation becomes much simpler when the first thing intercepted is the signaling channel that carries information to set up telephone calls. In civilian and many military use, this channel will carry messages in Signaling System 7 protocols. Retrospective analysis of telephone calls can be made from call detail records (CDR) used for billing the calls. Monitoring friendly communicationsMore a part of communications security than true intelligence collection, SIGINT units still may have the responsibility of monitoring one's own communications or other electronic emissions, to avoid providing intelligence to the enemy. For example, a security monitor may hear an individual transmitting inappropriate information over an unencrypted radio network, or simply one that is not authorized for the type of information being given. If immediately calling attention to the violation would not create an even greater security risk, the monitor will call out one of the BEADWINDOW codes[5] used by Australia, Canada, New Zealand, the United Kingdom, the United States, and other nations working under their procedures. Standard BEADWINDOW codes (e.g., "BEADWINDOW 2") include:
In WWII, for example, the Japanese Navy made possible the interception and death of the Combined Fleet commander, Admiral Isoroku Yamamoto, by BEADWINDOW 5 and 7 violations. They identified a key person's movement over a low-security cryptosystem. References
|