|
Transmission Security
Transmission security (TRANSEC) is the component of communications security ( COMSEC) that results from the application of measures designed to protect transmissions from interception and exploitation by means other than cryptanalysis. Goals of transmission security include: * Low probability of interception (LPI) * Low probability of detection (LPD) * Antijam — resistance to jamming (EPM or ECCM) Methods used to achieve transmission security include frequency hopping and spread spectrum where the required pseudorandom sequence generation is controlled by a cryptographic algorithm and key. Such keys are known as transmission security keys (TSK). Modern U.S. and NATO TRANSEC-equipped radios include SINCGARS and HAVE QUICK. See also * Electronic warfare Electronic warfare (EW) is any action involving the use of the electromagnetic spectrum (EM spectrum) or directed energy to control the spectrum, attack an enemy, or impede enemy assaults. The purpose of electronic warfar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptanalysis
Cryptanalysis (from the Greek ''kryptós'', "hidden", and ''analýein'', "to analyze") refers to the process of analyzing information systems in order to understand hidden aspects of the systems. Cryptanalysis is used to breach cryptographic security systems and gain access to the contents of encrypted messages, even if the cryptographic key is unknown. In addition to mathematical analysis of cryptographic algorithms, cryptanalysis includes the study of side-channel attacks that do not target weaknesses in the cryptographic algorithms themselves, but instead exploit weaknesses in their implementation. Even though the goal has been the same, the methods and techniques of cryptanalysis have changed drastically through the history of cryptography, adapting to increasing cryptographic complexity, ranging from the pen-and-paper methods of the past, through machines like the British Bombes and Colossus computers at Bletchley Park in World War II, to the mathematically advanced comput ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low Probability Of Intercept
A low-probability-of-intercept radar (LPIR) is a radar employing measures to avoid detection by passive radar detection equipment (such as a radar warning receiver (RWR), or electronic support receiver) while it is searching for a target or engaged in target tracking. This characteristic is desirable in a radar because it allows finding and tracking an opponent without alerting them to the radar's presence. This also protects the radar installation from anti-radiation missiles (ARMs). LPI measures include: *Power management and high duty cycle, meaning the transmitter is on most of the time (long integration times) *Wide bandwidth (or Ultra-wideband) *Frequency Agility, and frequency selection *Advanced/irregular scan patterns *Coded pulses (coherent detection) *High processing gain *Low sidelobe antennas Rationale Radar systems work by sending out a signal and then listening for its echo off distant objects. Each of these paths, to and from the target, is subject to the inverse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Jamming
Radio jamming is the deliberate jamming, blocking or interference with wireless communications.https://apps.fcc.gov/edocs_public/attachmatch/DA-12-347A1.pdf Enforcement Advisory No. 2012-02 FCC Enforcement Advisory Cell Jammers, GPS Jammers, and Other Jamming Devices Consumer Alert: Using or Importing Jammers is Illegal In some cases, jammers work by the transmission of radio signals that disrupt communications by decreasing the signal-to-noise ratio. The concept can be used in wireless data networks to disrupt information flow. It is a common form of censorship in totalitarian countries, in order to prevent foreign radio stations in border areas from reaching the country. Jamming is usually distinguished from interference that can occur due to device malfunctions or other accidental circumstances. Devices that simply cause interference are regulated differently. Unintentional "jamming" occurs when an operator transmits on a busy frequency without first checking whether it is in u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronic Counter-countermeasures
Electronic counter-countermeasures (ECCM) is a part of electronic warfare which includes a variety of practices which attempt to reduce or eliminate the effect of electronic countermeasures (ECM) on electronic sensors aboard vehicles, ships and aircraft and weapons such as missiles. ECCM is also known as electronic protective measures (EPM), chiefly in Europe. In practice, EPM often means resistance to jamming. A more detailed description defines it as the electronic warfare operations taken by a radar to offset the enemy's countermeasure. History Ever since electronics have been used in battle in an attempt to gain superiority over the enemy, effort has been spent on techniques to reduce the effectiveness of those electronics. More recently, sensors and weapons are being modified to deal with this threat. One of the most common types of ECM is radar jamming or spoofing. This originated with the Royal Air Force's use of what they codenamed ''Window'' during World War II, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency Hopping
Frequency-hopping spread spectrum (FHSS) is a method of transmitting radio signals by rapidly changing the carrier frequency among many distinct frequencies occupying a large spectral band. The changes are controlled by a code known to both transmitter and receiver. FHSS is used to avoid interference, to prevent eavesdropping, and to enable code-division multiple access (CDMA) communications. The available frequency band is divided into smaller sub-bands. Signals rapidly change ("hop") their carrier frequencies among the center frequencies of these sub-bands in a predetermined order. Interference at a specific frequency will affect the signal only during a short interval. FHSS offers four main advantages over a fixed-frequency transmission: # FHSS signals are highly resistant to narrowband interference because the signal hops to a different frequency band. # Signals are difficult to intercept if the frequency-hopping pattern is not known. # Jamming is also difficult if the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spread Spectrum
In telecommunication and radio communication, spread-spectrum techniques are methods by which a signal (e.g., an electrical, electromagnetic, or acoustic signal) generated with a particular bandwidth is deliberately spread in the frequency domain, resulting in a signal with a wider bandwidth. These techniques are used for a variety of reasons, including the establishment of secure communications, increasing resistance to natural interference, noise, and jamming, to prevent detection, to limit power flux density (e.g., in satellite downlinks), and to enable multiple-access communications. Telecommunications Spread spectrum generally makes use of a sequential noise-like signal structure to spread the normally narrowband information signal over a relatively wideband (radio) band of frequencies. The receiver correlates the received signals to retrieve the original information signal. Originally there were two motivations: either to resist enemy efforts to jam the communications ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudorandom
A pseudorandom sequence of numbers is one that appears to be statistically random, despite having been produced by a completely deterministic Determinism is a philosophical view, where all events are determined completely by previously existing causes. Deterministic theories throughout the history of philosophy have developed from diverse and sometimes overlapping motives and consi ... and repeatable process. Background The generation of random numbers has many uses, such as for sampling (statistics), random sampling, Monte Carlo methods, board games, or gambling. In physics, however, most processes, such as gravitational acceleration, are deterministic, meaning that they always produce the same outcome from the same starting point. Some notable exceptions are radioactive decay and quantum measurement, which are both modeled as being truly random processes in the underlying physics. Since these processes are not practical sources of random numbers, people use pseudoran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptographic
Cryptography, or cryptology (from grc, , translit=kryptós "hidden, secret"; and ''graphein'', "to write", or '' -logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of adversarial behavior. More generally, cryptography is about constructing and analyzing protocols that prevent third parties or the public from reading private messages. Modern cryptography exists at the intersection of the disciplines of mathematics, computer science, information security, electrical engineering, digital signal processing, physics, and others. Core concepts related to information security ( data confidentiality, data integrity, authentication, and non-repudiation) are also central to cryptography. Practical applications of cryptography include electronic commerce, chip-based payment cards, digital currencies, computer passwords, and military communications. Cryptography prior to the modern age was effectively synonymous wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Key (cryptography)
A key in cryptography is a piece of information, usually a string of numbers or letters that are stored in a file, which, when processed through a cryptographic algorithm, can encode or decode cryptographic data. Based on the used method, the key can be different sizes and varieties, but in all cases, the strength of the encryption relies on the security of the key being maintained. A key’s security strength is dependent on its algorithm, the size of the key, the generation of the key, and the process of key exchange. Scope The key is what is used to encrypt data from plaintext to ciphertext. There are different methods for utilizing keys and encryption. Symmetric cryptography Symmetric cryptography refers to the practice of the same key being used for both encryption and decryption. Asymmetric cryptography Asymmetric cryptography has separate keys for encrypting and decrypting. These keys are known as the public and private keys, respectively. Purpose Since the key pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NATO
The North Atlantic Treaty Organization (NATO, ; french: Organisation du traité de l'Atlantique nord, ), also called the North Atlantic Alliance, is an intergovernmental military alliance between 30 member states – 28 European and two North American. Established in the aftermath of World War II, the organization implemented the North Atlantic Treaty, signed in Washington, D.C., on 4 April 1949. NATO is a collective security system: its independent member states agree to defend each other against attacks by third parties. During the Cold War, NATO operated as a check on the perceived threat posed by the Soviet Union. The alliance remained in place after the dissolution of the Soviet Union and has been involved in military operations in the Balkans, the Middle East, South Asia, and Africa. The organization's motto is ''animus in consulendo liber'' (Latin for "a mind unfettered in deliberation"). NATO's main headquarters are located in Brussels, Belgium, while NATO ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SINCGARS
Single Channel Ground and Airborne Radio System (SINCGARS) is a Combat-net radio (CNR) used by U.S. and allied military forces. The CNR network is designed around three systems: SINCGARS, the high frequency (HF) radio, and the SC tactical satellite (TACSAT). Each system has different capabilities and transmission characteristics. SINCGARS is a family of user-owned and operated, very high frequency-frequency modulation (VHF-FM) CNRs. In the CNR network, the SINCGARS’ primary role is voice transmission for command and control (C2) between surface and airborne C2 assets. SINCGARS can transmit and receive secure data and facsimile transmissions through simple connections with various data terminal equipment. SINCGARS features provide communications interoperability for the Army, Marine, Navy, and Air Force, thus contributing to successful combat operations. It is also consistent with North Atlantic Treaty Organization interoperability requirements. The radios, which is hand ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
