|
TEMPEST is a National Security Agency specification and NATO certification〔 〕〔 〕 referring to spying on information systems through leaking emanations, including unintentional radio or electrical signals, sounds, and vibrations.〔(【引用サイトリンク】title=How Old IsTEMPEST? )〕 TEMPEST covers both methods to spy upon others and also 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).〔() 〕 The NSA methods for spying upon computer emissions are classified, but some of the protection standards have been released by either the NSA or the Department of Defense. Protecting equipment from spying is done with distance, shielding, filtering and masking. The TEMPEST standards mandate elements such as equipment distance from walls, amount of shielding in buildings and equipment, and distance separating wires carrying classified vs. unclassified materials,〔 filters on cables, and even distance and shielding between wires/equipment and building pipes. Noise can also protect information by masking the actual data.〔 While much of TEMPEST is about leaking electromagnetic emanations, it also encompasses sounds or mechanical vibrations.〔 For example, it is possible to log a user's keystrokes using the motion sensor inside smartphones. Compromising emissions are defined as unintentional intelligence-bearing signals which, if intercepted and analyzed, may disclose the information transmitted, received, handled, or otherwise processed by any information-processing equipment. ==Shielding standards== Many specifics of the TEMPEST standards are classified, but some elements are public. Current United States and NATO Tempest standards define three levels of protection requirements: * NATO SDIP-27 Level A (formerly AMSG 720B) and USA NSTISSAM Level I :''"Compromising Emanations Laboratory Test Standard"'' :This is the strictest standard for devices that will be operated in ''NATO Zone 0'' environments, where it is assumed that an attacker has almost immediate access (e.g. neighbouring room, 1 m distance). * NATO SDIP-27 Level B (formerly AMSG 788A) and USA NSTISSAM Level II :''"Laboratory Test Standard for Protected Facility Equipment"'' :This is a slightly relaxed standard for devices that are operated in ''NATO Zone 1'' environments, where it is assumed that an attacker cannot get closer than about 20 m (or where building materials ensure an attenuation equivalent to the free-space attenuation of this distance). * NATO SDIP-27 Level C (formerly AMSG 784) and USA NSTISSAM Level III :''"Laboratory Test Standard for Tactical Mobile Equipment/Systems"'' :An even more relaxed standard for devices operated in ''NATO Zone 2'' environments, where attackers have to deal with about 100 m worth of free-space attenuation (or equivalent attenuation through building materials). Additional standards include: * NATO SDIP-29 (formerly AMSG 719G) :''"Installation of Electrical Equipment for the Processing of Classified Information"'' :This standard defines installation requirements, for example in respect to grounding and cable distances. * AMSG 799B :''"NATO Zoning Procedures"'' :Defines an attenuation measurement procedure, according to which individual rooms within a security perimeter can be classified into Zone 0, Zone 1, Zone 2, or Zone 3, which then determines what shielding test standard is required for equipment that processes secret data in these rooms. The NSA and Department of Defense have declassified some TEMPEST elements after Freedom of Information Act requests, but the documents black out many key values and descriptions. The declassified version of the TEMPEST test standard is heavily redacted, with emanation limits and test procedures blacked out. A redacted version of the introductory Tempest handbook NACSIM 5000 was publicly released in December 2000. Additionally, the current NATO standard SDIP-27 (before 2006 known as AMSG 720B, AMSG 788A, and AMSG 784) is still classified. Despite this, some declassified documents give information on the shielding required by TEMPEST standards. For example, Military Handbook 1195 includes the chart at the right, showing electromagnetic shielding requirements at different frequencies. A declassified NSA specification for shielded enclosures offers similar shielding values, requiring, "a minimum of 100 dB insertion loss from 1 KHz to 10 GHz." Since much of the current requirements are still classified, there are no publicly available correlations between this 100 dB shielding requirement and the newer zone-based shielding standards. In addition, many separation distance requirements and other elements are provided by the declassified NSA red-black installation guidance, NSTISSAM TEMPEST/2-95. The United States Air Force has published a few mandatory standards regarding Emission Security: * (Instruction AFI 33-203 Vol 1 ), Emission Security (Soon to be AFSSI 7700) * (Instruction AFI 33-203 Vol 3 ), EMSEC Countermeasures Reviews (Soon to be AFSSI 7702) * (Instruction AFI 33-201 Vol 8 ), Protected Distributed Systems (Soon to be AFSSI 7703) 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Tempest (codename)」の詳細全文を読む スポンサード リンク
|