Eavesdropping is the act of secretly or stealthily listening to the private conversation or communications of others without their consent.[1] The practice is widely regarded as unethical, and in many jurisdictions is illegal.

Henri Adolphe Laissement Kardinäle im Vorzimmer 1895
Cardinals eavesdropping in the Vatican. A painting by Henri Adolphe Laissement, 1895
Audio drill
"Belly-buster" hand-crank audio drill, used during the late 1950s and early 1960s to drill holes into masonry for implanting audio devices


The verb eavesdrop is a back-formation from the noun eavesdropper ("a person who eavesdrops"), which was formed from the related noun eavesdrop ("the dripping of water from the eaves of a house; the ground on which such water falls").[2]

An eavesdropper was someone who would hang from the eave of a building so as to hear what is said within. The PBS documentaries, Inside the Court of Henry VIII (April 8, 2015)[3] and Secrets of Henry VIII’s Palace (June 30, 2013) include segments that display and discuss "eavedrops", carved wooden figures Henry VIII had built into the eaves (overhanging edges of the beams in the ceiling) of Hampton Court to discourage unwanted gossip or dissension from the King's wishes and rule, to foment paranoia and fear,[3] and demonstrate that everything said there was being overheard; literally, that the walls had ears.[4]


Eavesdropping vectors include telephone lines, cellular networks, email, and other methods of private instant messaging. VoIP communications software is also vulnerable to electronic eavesdropping via infections such as trojans.[1]

Network attacks

Network eavesdropping is a network layer attack that focuses on capturing small packets from the network transmitted by other computers and reading the data content in search of any type of information. This type of network attack is generally one of the most effective as a lack of encryption services are used. It is also linked to the collection of metadata. Those who perform this type of attack are generally black-hat hackers; however, government agencies, such as the National Security Agency, have also been connected.

See also


  1. ^ a b Garner, p. 550
  2. ^ "eavesdrop - Definition of eavesdrop in English by Oxford Dictionaries". Oxford Dictionaries - English.
  3. ^ a b Inside the Court of Henry VIII. Public Broadcasting Service. April 8, 2016.
  4. ^ Stollznow, Karen (August 7, 2014). "Eavesdropping: etymology, meaning, and some creepy little statues". KarenStollznow.com.

External links

Anita Alvarez

Anita Alvarez (born January 16, 1960) is the former State's Attorney for Cook County, Illinois, United States. Alvarez was the first Hispanic woman elected to this position, after being the first Latina to win the Democratic nomination for state's attorney of Cook County.

Cordless telephone

A cordless telephone or portable telephone is a telephone in which the handset is portable and communicates with the body of the phone by radio, instead of being attached by a cord. The base station is connected to the telephone network through a telephone line as a corded telephone is, and also serves as a charger to charge the handset's batteries. The range is limited, usually to the same building or some short distance from the base station.

A cordless telephone differs from a mobile telephone by the limited range and by the base station on the subscriber premises. Current cordless telephone standards, such as PHS and DECT, have blurred the once clear-cut line between cordless and mobile telephones by implementing cell handoff (handover); various advanced features, such as data-transfer; and even, on a limited scale, international roaming. In specialized models, base stations are maintained by a commercial mobile network operator and users subscribe to the service.

In 1994, digital cordless phones in the 900 MHz frequency range were introduced. Digital signals allowed the phones to be more secure and decreased eavesdropping; it was relatively easy to eavesdrop on analog cordless phone conversations. In 1995, digital spread spectrum (DSS) was introduced for cordless phones. This technology enabled the digital voice transmission to be spread over multiple frequencies, improving privacy and reducing interference between different subscribers.

Unlike a corded telephone, a cordless telephone needs mains electricity to power the base station. The cordless handset is powered by a rechargeable battery, which is charged when the handset is stored in its cradle.


Countersurveillance refers to measures undertaken to prevent surveillance, including covert surveillance. Countersurveillance may include electronic methods such as technical surveillance counter-measures, the process of detecting surveillance devices, including covert listening devices, visual surveillance devices as well as countersurveillance software to thwart unwanted cybercrime, including accessing computing and mobile devices for various nefarious reasons (e.g. theft of financial, personal or corporate data). More often than not, countersurveillance will employ a set of actions (countermeasures) that, when followed, reduce the risk of surveillance. Countersurveillance is different from sousveillance (inverse surveillance), as the latter does not necessarily aim to prevent or reduce surveillance.

Covert listening device

A covert listening device, more commonly known as a bug or a wire, is usually a combination of a miniature radio transmitter with a microphone. The use of bugs, called bugging, is a common technique in surveillance, espionage and police investigations.

Self-contained electronic covert listening devices came into common use with intelligence agencies in the 1950's, when technology allowed for a suitable transmitter to be built into a relatively small package. By 1956, the U.S. Central Intelligence Agency was designing and building "Surveillance Transmitters" that employed transistors, which greatly reduced the size and power consumption. An all solid-state device had low enough power needs that it could be operated by small batteries, which revolutionized the business of covert listening.

A bug does not have to be a device specifically designed for the purpose of eavesdropping. For instance, with the right equipment, it is possible to remotely activate the microphone of cellular phones, even when a call is not being made, to listen to conversations in the vicinity of the phone.

IEC 62351

IEC 62351 is a standard developed by WG15 of IEC TC57. This is developed for handling the security of TC 57 series of protocols including IEC 60870-5 series, IEC 60870-6 series, IEC 61850 series, IEC 61970 series & IEC 61968 series. The different security objectives include authentication of data transfer through digital signatures, ensuring only authenticated access, prevention of eavesdropping, prevention of playback and spoofing, and intrusion detection.


Interdiction is a military term for the act of delaying, disrupting, or destroying enemy forces or supplies en route to the battle area. A distinction is often made between strategic and tactical interdiction. The former refers to operations whose effects are broad and long-term; tactical operations are designed to affect events rapidly and in a localized area.

The term interdiction is also used in criminology and law enforcement, such as in the U.S. War on Drugs and in immigration.The term interdiction is also used by the NSA when an electronics shipment is secretly intercepted by an intelligence service (domestic or foreign) for the purpose of implanting bugs before they reach their destination. According to Der Spiegel, the NSA's TAO group is able to divert shipping deliveries to its own "secret workshops" in a method called interdiction, where agents load malware onto the electronics or install malicious hardware that can give US intelligence agencies remote access. The report also indicates that the NSA, in collaboration with the CIA and FBI, routinely and secretly intercepts shipping deliveries for laptops or other computer accessories, such as a computer monitor or keyboard cables with hidden wireless transmitters bugs built-in for eavesdropping on video and keylogging.In July 2014 it was reported that handheld shipping scanners manufactured in China were found with pre-installed, weaponized malware which was capable of exfiltrating CRM data and financial data. These scanners are of the type used by many United States retailers and warehouses, as well as delivery services such as UPS and FedEx. The scanned data was copied and sent out to an established comprehensive command and control connection (CnC) to a Chinese botnet that was terminated at the Lanxiang Vocational School located in China.

Laser microphone

A laser microphone is a surveillance device that uses a laser beam to detect sound vibrations in a distant object. It can be used to eavesdrop with minimal chance of exposure.

The object is typically inside a room where a conversation is taking place and can be anything that can vibrate (for example, a picture on a wall) in response to the pressure waves created by noises present in the room. The object preferably has a smooth surface. The laser beam is directed into the room through a window, reflects off the object, and returns to a receiver that converts the beam to an audio signal. The beam may also be bounced off the window itself. The minute differences in the distance traveled by the light as it reflects from the vibrating object are detected interferometrically. The interferometer converts the variations to intensity variations, and electronics are used to convert these variations to signals that can be converted back to sound.

Narrative thread

A narrative thread, or plot thread (or, more ambiguously, a storyline), refers to particular elements and techniques of writing to center the story in the action or experience of characters rather than to relate a matter in a dry "all-knowing" sort of narration. Thus the narrative threads experienced by different but specific characters or sets of characters are those seen in the eyes of those characters that together form a plot element or subplot in the work of fiction. In this sense, each narrative thread is the narrative portion of a work that pertains to the world view of the participating characters cognizant of their piece of the whole, and they may be the villains, the protagonists, a supporting character, or a relatively disinterested official utilized by the author, each thread of which is woven together by the writer to create a work.

By utilizing different threads, the writer enables the reader to get pieces of the overall plot while positioning them to identify with the characters or experience the situation as if the reader were part of or eavesdropping upon the action the writer is divulging. This aids in the suspension of disbelief and engages the reader into the story as it develops.

A classic structure of narrative thread often used in both fiction and non-fiction writing is the monomyth, or hero's journey, with a beginning, a middle, and an end. First, typically the harmony of daily life is broken by a particularly dramatic event that leads into the main story. Then, second, the plot builds to a point of no return, from where the protagonist – who need not be a person but may be an organization or a community – has no choice but to deal with matters, and thus is tested. At this point, characteristically, there is conflict and the conflict intensifies. Third, and finally, harmony is reestablished by the conflict being solved, or at least explained in the case of non-fiction.

Overheard (film)

Overheard (traditional Chinese: 竊聽風雲; simplified Chinese: 窃听风云; pinyin: Qie Ting Feng Yun; Cantonese Yale: Sit Teng Fung Wan) is a 2009 Hong Kong crime thriller film written and directed by Alan Mak and Felix Chong, and produced by Henry Fong and Derek Yee. The film stars Lau Ching-wan, Louis Koo and Daniel Wu as a trio of police officers conducting surveillance on a public company. The film was released theatrically in Hong Kong on 30 July 2009. The sequel, Overheard 2, was released in 2011.

Quantum key distribution

Quantum key distribution (QKD) is a secure communication method which implements a cryptographic protocol involving components of quantum mechanics. It enables two parties to produce a shared random secret key known only to them, which can then be used to encrypt and decrypt messages. It is often incorrectly called quantum cryptography, as it is the best-known example of a quantum cryptographic task.

An important and unique property of quantum key distribution is the ability of the two communicating users to detect the presence of any third party trying to gain knowledge of the key. This results from a fundamental aspect of quantum mechanics: the process of measuring a quantum system in general disturbs the system. A third party trying to eavesdrop on the key must in some way measure it, thus introducing detectable anomalies. By using quantum superpositions or quantum entanglement and transmitting information in quantum states, a communication system can be implemented that detects eavesdropping. If the level of eavesdropping is below a certain threshold, a key can be produced that is guaranteed to be secure (i.e. the eavesdropper has no information about it), otherwise no secure key is possible and communication is aborted.

The security of encryption that uses quantum key distribution relies on the foundations of quantum mechanics, in contrast to traditional public key cryptography, which relies on the computational difficulty of certain mathematical functions, and cannot provide any mathematical proof as to the actual complexity of reversing the one-way functions used. QKD has provable security based on information theory, and forward secrecy.

Quantum key distribution is only used to produce and distribute a key, not to transmit any message data. This key can then be used with any chosen encryption algorithm to encrypt (and decrypt) a message, which can then be transmitted over a standard communication channel. The algorithm most commonly associated with QKD is the one-time pad, as it is provably secure when used with a secret, random key. In real-world situations, it is often also used with encryption using symmetric key algorithms like the Advanced Encryption Standard algorithm.

Special Collection Service

The Special Collection Service (SCS), codenamed F6, is a highly classified joint U.S. Central Intelligence Agency–National Security Agency program charged with inserting eavesdropping equipment in difficult-to-reach places, such as foreign embassies, communications centers, and foreign government installations. Established in the late 1970s and headquartered in Beltsville, Maryland, the SCS has been involved in operations ranging from the Cold War to the Global War on Terrorism.

According to documents leaked by Edward Snowden, the SCS is part of a larger global surveillance program known as STATEROOM.


In espionage and counterintelligence, surveillance ( or ) is the monitoring of behavior, activities, or other changing information for the purpose of influencing, managing, directing, or protecting people. This can include observation from a distance by means of electronic equipment (such as closed-circuit television (CCTV) cameras) or interception of electronically transmitted information (such as Internet traffic or phone calls). It can also include simple no- or relatively low-technology methods such as human intelligence agent and postal interception. The word surveillance comes from a French phrase for "watching over" (sur means "from above" and veiller means "to watch") and is in contrast to more recent developments such as sousveillance.Surveillance is used by governments for intelligence gathering, prevention of crime, the protection of a process, person, group or object, or the investigation of crime. It is also used by criminal organisations to plan and commit crimes, such as robbery and kidnapping, by businesses to gather intelligence, and by private investigators.

Surveillance can be viewed as a violation of privacy, and as such is often opposed by various civil liberties groups and activists. Liberal democracies have laws which restrict domestic government and private use of surveillance, usually limiting it to circumstances where public safety is at risk. Authoritarian government seldom have any domestic restrictions, and international espionage is common among all types of countries.

The area of surveillance is increasingly a topic of academic study, including through research centers, books, and peer-reviewed academic journals. "In the future, intelligence services might use the internet of things for identification, surveillance, monitoring, location tracking, and targeting for recruitment, or to gain access to networks or user credentials," Clapper said.

Telephone tapping

Telephone tapping (also wire tapping or wiretapping in American English) is the monitoring of telephone and Internet-based conversations by a third party, often by covert means. The wire tap received its name because, historically, the monitoring connection was an actual electrical tap on the telephone line. Legal wiretapping by a government agency is also called lawful interception. Passive wiretapping monitors or records the traffic, while active wiretapping alters or otherwise affects it.

The Inquirer

The Inquirer is a British technology tabloid website founded by Mike Magee after his departure from The Register (of which he was one of the founding members) in 2001. In 2006 the site was acquired by Dutch publisher Verenigde Nederlandse Uitgeverijen (VNU). Mike Magee later left The Inquirer in February 2008 to work on the IT Examiner.

Historically, the magazine was entirely Internet-based with its journalists living all over the world and filing copy online, though in recent years it has been edited from Incisive Media's offices in London.Although traditionally a 'red top', under Incisive Media it has put more weight behind its journalism, reducing the number of jibes at companies, and moved instead towards sponsored online debates in association with high-profile organisations, most recently, Intel.

The Shadow Factory

The Shadow Factory: The Ultra-Secret NSA from 9/11 to the Eavesdropping on America is a book on the National Security Agency by author James Bamford.

Tor (anonymity network)

Tor is free and open-source software for enabling anonymous communication. The name is derived from an acronym for the original software project name "The Onion Router". Tor directs Internet traffic through a free, worldwide, volunteer overlay network consisting of more than seven thousand relays to conceal a user's location and usage from anyone conducting network surveillance or traffic analysis. Using Tor makes it more difficult to trace Internet activity to the user: this includes "visits to Web sites, online posts, instant messages, and other communication forms". Tor's intended use is to protect the personal privacy of its users, as well as their freedom and ability to conduct confidential communication by keeping their Internet activities from being monitored.

Tor does not prevent an online service from determining when it is being accessed through Tor. Tor protects a user's privacy, but does not hide the fact that someone is using Tor. Some websites restrict allowances through Tor. For example, the MediaWiki TorBlock extension automatically restricts edits made through Tor, although Wikipedia allows some limited editing in exceptional circumstances.Onion routing is implemented by encryption in the application layer of a communication protocol stack, nested like the layers of an onion. Tor encrypts the data, including the next node destination IP address, multiple times and sends it through a virtual circuit comprising successive, random-selection Tor relays. Each relay decrypts a layer of encryption to reveal the next relay in the circuit to pass the remaining encrypted data on to it. The final relay decrypts the innermost layer of encryption and sends the original data to its destination without revealing or knowing the source IP address. Because the routing of the communication was partly concealed at every hop in the Tor circuit, this method eliminates any single point at which the communicating peers can be determined through network surveillance that relies upon knowing its source and destination.An adversary may try to de-anonymize the user by some means. One way this may be achieved is by exploiting vulnerable software on the user's computer. The NSA had a technique that targets a vulnerability – which they codenamed "EgotisticalGiraffe" – in an outdated Firefox browser version at one time bundled with the Tor package and, in general, targets Tor users for close monitoring under its XKeyscore program. Attacks against Tor are an active area of academic research which is welcomed by the Tor Project itself. The bulk of the funding for Tor's development has come from the federal government of the United States, initially through the Office of Naval Research and DARPA.


USA 202, previously NRO Launch 26 or NROL-26, is a classified spacecraft which is operated by the United States National Reconnaissance Office. It is an Advanced Orion ELINT satellite. According to Aviation Week, it "fundamentally involves America's biggest, most secret and expensive military spacecraft on board the world's largest rocket." The combined cost of the spacecraft and launch vehicle has been estimated to be over US$2 billion.Amateur astronomer observations suspected the satellite was eavesdropping on Thuraya 2 and this was reported to be confirmed by documents released on Sep 9, 2016 by The Intercept as part of the Snowden Files.

Van Eck phreaking

Van Eck phreaking is a form of eavesdropping in which special equipment is used to pick up side-band electromagnetic emissions from electronics devices that correlate to hidden signals or data for the purpose of recreating these signals or data in order to spy on the electronic device. Side-band electromagnetic radiation emissions are present in and, with the proper equipment, can be captured from keyboards, computer displays, printers, and other electronic devices.

In 1985, Wim van Eck published the first unclassified technical analysis of the security risks of emanations from computer monitors. This paper caused some consternation in the security community, which had previously believed that such monitoring was a highly sophisticated attack available only to governments; van Eck successfully eavesdropped on a real system, at a range of hundreds of metres, using just $15 worth of equipment plus a television set.

As a consequence of this research, such emanations are sometimes called "van Eck radiation", and the eavesdropping technique van Eck phreaking. Although government researchers were already aware of the danger, as Bell Labs noted this vulnerability to secure teleprinter communications during World War II and was able to produce 75% of the plaintext being processed in a secure facility from a distance of 80 feet. (24 metres) Additionally the NSA published Tempest Fundamentals, NSA-82-89, NACSIM 5000, National Security Agency (Classified) on February 1, 1982. In addition, the van Eck technique was successfully demonstrated to non-TEMPEST personnel in Korea during the Korean War in the 1950s.

While Phreaking is the process of exploiting telephone networks, it is used here because of its connection to eavesdropping. Van Eck phreaking of CRT displays is the process of eavesdropping on the contents of a CRT by detecting its electromagnetic emissions.

Vance Wilkins

Shirley Vance Wilkins, Jr. (born August 12, 1936) is a retired American politician of the Republican Party. He was a member of the Virginia House of Delegates from 1978-2002. In 2000 he became the first ever Republican Speaker of the Virginia House and first non-Democratic Speaker since the Readjuster Party controlled the House in the early 1880s.

Wilkins was considered the driving force in the expansion of Republican House membership in the 1980s and 1990s, especially after he became minority leader in 1992. In his first term as Speaker, he oversaw the redistricting of the House after the 2000 census that led to an increase in the Republican majority from 52-47 (1 independent) to 64-34 (2 independents) after the November 2001 election.

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