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A black room is part of a communication center (e.g. a
post office
A post office is a public facility and a retailer that provides mail services, such as accepting letters and parcels, providing post office boxes, and selling postage stamps, packaging, and stationery. Post offices may offer additional ser ...
) used by state officials to conduct
clandestine
Clandestine may refer to:
* Secrecy, the practice of hiding information from certain individuals or groups, perhaps while sharing it with other individuals
* Clandestine operation, a secret intelligence or military activity
Music and entertainme ...
interception and
surveillance of communications.
Typically, all letters or communications pass through the black room before being passed to the recipient. This practice had been in vogue since the establishment of postal and telegraph services, and was frequently used in France by the ministers of
Louis XVIII
Louis XVIII (Louis Stanislas Xavier; 17 November 1755 – 16 September 1824), known as the Desired (), was King of France from 1814 to 1824, except for a brief interruption during the Hundred Days in 1815. He spent twenty-three years in ...
and his followers as the ''
cabinet noir
In France, the ''cabinet noir'' ( French for " black room", also known as the "dark chamber" or "black chamber") was a government intelligence-gathering office, usually within a postal service, where correspondence between persons or entities wa ...
'' (French for "black room").
In modern American
network operations center
A network operations center (NOC, pronounced like the word ''knock''), also known as a "network management center", is one or more locations from which network monitoring and control, or network management, is exercised over a computer, teleco ...
s,
optical splitter
A beam splitter or ''beamsplitter'' is an optical device that splits a beam of light into a transmitted and a reflected beam. It is a crucial part of many optical experimental and measurement systems, such as interferometers, also finding wide ...
s divert a percentage of the
laser light
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The firs ...
from all incoming and outgoing
fiber-optic cable
A fiber-optic cable, also known as an optical-fiber cable, is an assembly similar to an electrical cable, but containing one or more optical fibers that are used to carry light. The optical fiber elements are typically individually coated with ...
s to the secret room.
An example is
Room 641A
Room 641A is a telecommunication interception facility operated by AT&T for the U.S. National Security Agency, as part of its warrantless surveillance program as authorized by the Patriot Act. The facility commenced operations in 2003 and its ...
in the
SBC Communications building in San Francisco.
[
The term ''black room'' or '']black chamber
The Black Chamber (1919–1929), also known as the Cipher Bureau, was the United States' first peacetime cryptanalytic organization, and a forerunner of the National Security Agency. The only prior codes and cypher organizations maintained by th ...
'' has also been used to refer to any place or organisation dedicated to code-breaking
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 sec ...
.
See also
*Bulgarian medieval cryptography
*Black Chamber
The Black Chamber (1919–1929), also known as the Cipher Bureau, was the United States' first peacetime cryptanalytic organization, and a forerunner of the National Security Agency. The only prior codes and cypher organizations maintained by th ...
*Black site
In military terminology, a black site is a location at which an unacknowledged black operation or black project is conducted. According to the Associated Press, "Black sites are clandestine jails where prisoners generally are not charged with ...
* ECHELON
*Postal censorship
Postal censorship is the inspection or examination of mail, most often by governments. It can include opening, reading and total or selective obliteration of letters and their contents, as well as covers, postcards, parcels and other postal pa ...
*Secrecy of correspondence
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The secrecy of correspondence (german: Briefgeheimnis, french: secret de la correspondance) or literally translated as secrecy of letters, is a fundamental legal principle enshrined in the constitutions of several European countries. It ...
References
{{reflist
Privacy of telecommunications
Postal systems
Black room