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- Date: Fri, 19 Jan 90 19:13:44 -0500
- From: cjs%cwru@cwjcc.ins.cwru.edu (Christopher J. Seline (CJS@CWRU.CWRU.EDU))
-
- The following is a prepublication draft of an article on TEMPEST. I am posting
- it to this news group in the hope that it will:
- (1) stimulate discussion of this issue;
- (2) expose any technical errors in the document;
- (3) solicit new sources of information;
- (4) uncover anything I have forgotten to cover.
-
- I will be unable to monitor the discussions of the article. Therefore, PLEASE
- post your comments to the news group BUT SEND ME A COPY AT THE ADDRESS LISTED
- BELOW.
-
- I have gotten a number of mail messages about the format of this
- article. Some explanation is in order: The numbered paragraphs
- following "____________________" on each page are footnotes. I suggest
- printing out the document rather than reading it on your CRT.
-
- Thanks you in advance.
-
- Christopher Seline
- cjs@cwru.cwru.edu
- cjs@cwru.bitnet
-
- (c) 1990 Christopher J. Seline
- =============================================================================
- <Start Print Job>
- <New Page>
- Eavesdropping On
- the Electromagnetic Emanations
- of Digital Equipment:
- The Laws of Canada,
- England and the United States
-
- This document is a rough
- draft. The Legal
- Sections are overviews.
- T h e y w i l l b e
- significantly expanded in
- the next version.
-
- We in this country, in this generation, are -- by
- destiny rather than choice -- the watchmen on the
- walls of world freedom.[1]
- -President John F.
- Kennedy
-
- _____________________
-
- 1. Undelivered speech of President John F. Kennedy, Dallas
- Citizens Council (Nov. 22, 1963) 35-36.
-
- <New Page>
- In the novel 1984, George Orwell foretold a future
- where individuals had no expectation of privacy because the
- state monopolized the technology of spying. The government
- watched the actions of its subjects from birth to death. No
- one could protect himself because surveillance and counter-
- surveillance technology was controlled by the government.
- This note explores the legal status of a surveillance
- technology ruefully known as TEMPEST[2]. Using TEMPEST
- technology the information in any digital device may be
- intercepted and reconstructed into useful intelligence
- without the operative ever having to come near his target.
- The technology is especially useful in the interception of
- information stored in digital computers or displayed on
- computer terminals.
- The use of TEMPEST is not illegal under the laws of the
- United States[3], or England. Canada has specific laws
- criminalizing TEMPEST eavesdropping but the laws do more to
- hinder surveillance countermeasures than to prevent TEMPEST
- surveillance. In the United States it is illegal for an
- individual to take effective counter-measures against
- TEMPEST surveillance. This leads to the conundrum that it
- is legal for individuals and the government to invade the
- privacy of others but illegal for individuals to take steps
- to protect their privacy.
- The author would like to suggest that the solution to
- this conundrum is straightforward. Information on
- _____________________
-
- 2. TEMPEST is an acronym for Transient Electromagnetic Pulse
- Emanation Standard. This standard sets forth the official views
- of the United States on the amount of electromagnetic radiation
- that a device may emit without compromising the information it is
- processing. TEMPEST is a defensive standard; a device which
- conforms to this standard is referred to as TEMPEST Certified.
- The United States government has refused to declassify the
- acronym for devices used to intercept the electromagnetic
- information of non-TEMPEST Certified devices. For this note,
- these devices and the technology behind them will also be
- referred to as TEMPEST; in which case, TEMPEST stands for
- Transient Electromagnetic Pulse Surveillance Technology.
- The United States government refuses to release details
- regarding TEMPEST and continues an organized effort to censor the
- dissemination of information about it. For example the NSA
- succeeded in shutting down a Wang Laboratories presentation on
- TEMPEST Certified equipment by classifying the contents of the
- speech and threatening to prosecute the speaker with revealing
- classified information. [cite coming].
-
- 3. This Note will not discuses how TEMPEST relates to the
- Warrant Requirement under the United States Constitution. Nor
- will it discuss the Constitutional exclusion of foreign nationals
- from the Warrant Requirement.
-
- <New Page>
- protecting privacy under TEMPEST should be made freely
- available; TEMPEST Certified equipment should be legally
- available; and organizations possessing private information
- should be required by law to protect that information
- through good computer security practices and the use of
- TEMPEST Certified equipment.
-
- I. INTELLIGENCE GATHERING
- Spying is divided by professionals into two main types:
- human intelligence gathering (HUMINT) and electronic
- intelligence gathering (ELINT). As the names imply, HUMINT
- relies on human operatives, and ELINT relies on
- technological operatives. In the past HUMINT was the sole
- method for collecting intelligence.[4] The HUMINT operative
- would steal important papers, observe troop and weapon
- movements[5], lure people into his confidences to extract
- secrets, and stand under the eavesdrip[6] of houses,
- eavesdropping on the occupants.
- As technology has progressed, tasks that once could
- only be performed by humans have been taken over by
- machines. So it has been with spying. Modern satellite
- technology allows troop and weapons movements to be observed
- with greater precision and from greater distances than a
- human spy could ever hope to accomplish. The theft of
- documents and eavesdropping on conversations may now be
- performed electronically. This means greater safety for the
- human operative, whose only involvement may be the placing
- of the initial ELINT devices. This has led to the
- ascendancy of ELINT over HUMINT because the placement and
- _____________________
-
- 4. HUMINT has been used by the United States since the
- Revolution. "The necessity of procuring good intelligence is
- apparent & need not be further urged -- All that remains for me
- to add is, that you keep the whole matter as secret as possible.
- For upon Secrecy, Success depends in Most Enterprises of the
- kind, and for want of it, they are generally defeated, however
- well planned & promising a favorable issue." Letter of George
- Washington (Jul. 26, 1777).
-
- 5. "... I wish you to take every possible pains in your powers,
- by sending trusty persons to Staten Island in whom you can
- confide, to obtain Intelligence of the Enemy's situation &
- numbers -- what kind of Troops they are, and what Guards they
- have -- their strength & where posted." Id.
-
- 6. Eavesdrip is an Anglo-Saxon word, and refers to the wide
- overhanging eaves used to prevent rain from falling close to a
- house's foundation. The eavesdrip provided "a sheltered place
- where one could hide to listen clandestinely to conversation
- within the house." W. MORRIS & M. MORRIS, MORRIS DICTIONARY OF
- WORD AND PHRASE ORIGINS, 198 (1977).
-
- <New Page>
- monitoring of ELINT devices may be performed by a technician
- who has no training in the art of spying. The gathered
- intelligence may be processed by an intelligence expert,
- perhaps thousands of miles away, with no need of field
- experience.
- ELINT has a number of other advantages over HUMINT. If
- a spy is caught his existence could embarrass his employing
- state and he could be forced into giving up the identities
- of his compatriots or other important information. By its
- very nature, a discovered ELINT device (bug) cannot give up
- any information; and the ubiquitous nature of bugs provides
- the principle state with the ability to plausibly deny
- ownership or involvement.
- ELINT devices fall into two broad categories:
- trespassatory and non-trespassatory. Trespassatory bugs
- require some type of trespass in order for them to function.
- A transmitter might require the physical invasion of the
- target premises for placement, or a microphone might be
- surreptitiously attached to the outside of a window. A
- telephone transmitter can be placed anywhere on the phone
- line, including at the central switch. The trespass comes
- either when it is physically attached to the phone line, or
- if it is inductive, when placed in close proximity to the
- phone line. Even microwave bugs require the placement of
- the resonator cone within the target premises.[7]
- Non-trespassatory ELINT devices work by receiving
- electromagnetic radiation (EMR) as it radiates through the
- aether, and do not require the placement of bugs. Methods
- include intercepting[8] information transmitted by satellite,
- microwave, and radio, including mobile and cellular phone
- transmissions. This information was purposely transmitted
- with the intent that some intended person or persons would
- receive it.
- Non-trespassatory ELINT also includes the interception
- of information that was never intended to be transmitted.
- All electronic devices emit electromagnetic radiation. Some
- of the radiation, as with radio waves, is intended to
- transmit information. Much of this radiation is not
- intended to transmit information and is merely incidental to
-
- _____________________
-
- 7. Pursglove, How Russian Spy Radios Work, RADIO ELECTRONICS,
- 89-91 (Jan 1962).
-
- 8. Interception is an espionage term of art and should be
- differentiated from its more common usage. When information is
- intercepted, the interceptor as well as the intended recipient
- receive the information. Interception when not used as a term of
- art refers to one person receiving something intended for someone
- else; the intended recipient never receives what he was intended
- to receive.
-
- <New Page>
- whatever work the target device is performing.[9] This
- information can be intercepted and reconstructed into a
- coherent form. With current TEMPEST technology it is
- possible to reconstruct the contents of computer video
- display terminal (VDU) screens from up to a kilometer
- distant[10]; reconstructing the contents of a computer's
- _____________________
-
- 9. There are two types of emissions, conducted and radiated.
- Radiated emissions are formed when components or cables act as
- antennas for transmit the EMR; when radiation is conducted along
- cables or other connections but not radiated it is referred to as
- "conducted". Sources include cables, the ground loop, printed
- circuit boards, internal wires, the power supply to power line
- coupling, the cable to cable coupling, switching transistors, and
- high-power amplifiers. WHITE & M. MARDIGUIAN, EMI CONTROL
- METHODOLOGY AND PROCEDURES, 10.1 (1985).
- "[C]ables may act as an antenna to transmit the signals
- directly or even both receive the signals and re-emit them
- further away from the source equipment. It is possible that
- cables acting as an antenna in such a manner could transmit the
- signals much more efficiently than the equipment itself...A
- similar effect may occur with metal pipes such as those for
- domestic water supplies. ... If an earthing [(grounding)] system
- is not installed correctly such that there is a path in the
- circuit with a very high resistance (for example where paint
- prevents conduction and is acting as an insulator), then the
- whole earthing system could well act in a similar fashion to an
- antenna. ... [For a VDU] the strongest signals, or harmonics
- thereof, are usually between 60-250 MHz approximately. There
- have however been noticeable exception of extremely strong
- emissions in the television bands and at higher frequencies
- between 450-800 MHz. Potts, Emission Security, 3 COMPUTER LAW
- AND SECURITY REPORT 27 (1988).
-
- 10. The TEMPEST ELINT operator can distinguish between different
- VDUs in the same room because of the different EMR
- characteristics of both homo and heterogeneous units. "[T]here
- is little comparison between EMR characteristics from otherwise
- comparable equipment. Only if the [VDU] was made with exactly
- the same components is there any similarity. If some of the
- components have come from a different batch, have been updated in
- some way, and especially if they are from a different
- manufacturer, then completely different results are obtained. In
- this way a different mark or version of the same [VDU] will emit
- different signals. Additionally because of the variation of
- manufacturing standards between counties, two [VDUs] made by the
- same company but sourced from different counties will have
- entirely different EMR signal characteristics...From this it way
- be thought that there is such a jumble of emissions around, that
- it would not be possible to isolate those from any one particular
- source. Again, this is not the case. Most received signals have
-
- <New Page>
- memory or the contents of its mass storage devices is more
- complicated and must be performed from a closer distance.[11]
- The reconstruction of information via EMR, a process for
- which the United States government refuses to declassify
- either the exact technique or even its name[12], is not
- limited to computers and digital devices but is applicable
- to all devices that generate electromagnetic radiation.[13]
- TEMPEST is especially effective against VDUs because they
- produce a very high level of EMR.[14]
- _____________________
-
- a different line synchronization, due to design, reflection,
- interference or variation of component tolerances. So that if
- for instance there are three different signals on the same
- frequency ... by fine tuning of the RF receiver, antenna
- manipulation and modification of line synchronization, it is
- possible to lock onto each of the three signals separately and so
- read the screen information. By similar techniques, it is
- entirely possible to discriminate between individual items of
- equipment in the same room." Potts, supra note 9.
- For a discussion of the TEMPEST ELINT threat See e.g.,
- Memory Bank, AMERICAN BANKER 20 (Apr 1 1985); Emissions from Bank
- Computer Systems Make Eavesdropping Easy, Expert Says, AMERICAN
- BANKER 1 (Mar 26 1985); CRT spying: a threat to corporate
- security, PC WEEK (Mar 10 1987).
-
- 11. TEMPEST is concerned with the transient electromagnetic
- pulses formed by digital equipment. All electronic equipment
- radiates EMR which may be reconstructed. Digital equipment
- processes information as 1's and 0's--on's or off's. Because of
- this, digital equipment gives off pulses of EMR. These pulses
- are easier to reconstruct at a distance than the non-pulse EMR
- given off by analog equipment. For a thorough discussion the
- radiation problems of broadband digital information see e.g.
- military standard MIL-STD-461 REO2; White supra note 9, 10.2.
-
- 12. See supra note 2.
-
- 13. Of special interest to ELINT collectors are EMR from
- computers, communications centers and avionics. Schultz,
- Defeating Ivan with TEMPEST, DEFENSE ELECTRONICS 64 (June 1983).
-
- 14. The picture on a CRT screen is built up of picture
- elements (pixels) organized in lines across the screen. The
- pixels are made of material that fluoresces when struck with
- energy. The energy is produced by a beam of electrons fired from
- an electron gun in the back of the picture tube. The electron
- beam scans the screen of the CRT in a regular repetitive manner.
- When the voltage of the beam is high then the pixel it is focused
- upon emits photons and appears as a dot on the screen. By
- selectively firing the gun as it scans across the face of the
- CRT, the pixels form characters on the CRT screen.
-
- <New Page>
- ELINT is not limited to governments. It is routinely
- used by individuals for their own purposes. Almost all
- forms of ELINT are available to the individual with either
- the technological expertise or the money to hire someone
- with the expertise. Governments have attempted to
- criminalize all use of ELINT by their subjects--to protect
- the privacy of both the government and the population.
-
- II. UNITED STATES LAW
- In the United States, Title III of the Omnibus Streets
- and Crimes Act of 1968[15] criminalizes trespassatory ELINT as
- the intentional interception of wire communications.[16] As
- originally passed, Title III did not prohibit non-
-
- _____________________
-
- The pixels glow for only a very short time and must be
- routinely struck by the electron beam to stay lit. To maintain
- the light output of all the pixels that are supposed to be lit,
- the electron beam traverses the entire CRT screen sixty times a
- second. Every time the beam fires it causes a high voltage EMR
- emission. This EMR can be used to reconstruct the contents of
- the target CRT screen. TEMPEST ELINT equipment designed to
- reconstruct the information synchronizes its CRT with the target
- CRT. First, it uses the EMR to synchronize its electron gun with
- the electron gun in the target CRT. Then, when the TEMPEST ELINT
- unit detects EMR indicating that the target CRT fired on a pixel,
- the TEMPEST ELINT unit fires the electron gun of its CRT. The
- ELINT CRT is in perfect synchronism with the target CRT; when the
- target lights a pixel, a corresponding pixel on the TEMPEST ELINT
- CRT is lit. The exact picture on the target CRT will appear on
- the TEMPEST ELINT CRT. Any changes on the target screen will be
- instantly reflected in the TEMPEST ELINT screen.
- TEMPEST Certified equipment gives off emissions levels that
- are too faint to be readily detected. Certification levels are
- set out in National Communications Security Information
- Memorandum 5100A (NACSIM 5100A). "[E]mission levels are
- expressed in the time and frequency domain, broadband or narrow
- band in terms of the frequency domain, and in terms of conducted
- or radiated emissions." White, supra, note 9, 10.1.
- For a thorough though purposely misleading discussion of
- TEMPEST ELINT see Van Eck, Electromagnetic Radiation from Video
- Display units: An Eavesdropping Risk?, 4 Computers & Security 269
- (1985).
-
- 15. Pub. L. No. 90-351, 82 Stat. 197. The Act criminalizes
- trespassatory ELINT by individuals as well as governmental
- agents. cf. Katz v. United States, 389 U.S. 347 (1967) (Fourth
- Amendment prohibits surveillance by government not individuals.)
-
- 16. 18 U.S.C. 2511(1)(a).
-
- <New Page>
- trespassatory ELINT,[17] because courts found that non-wire
- communication lacked any expectation of p2IIIrivacy.[18] The
- Electronic Communications Privacy Act of 1986[19] amended
- Title III to include non-wire communication. ECPA was
- specifically designed to include electronic mail, inter-
- computer communications, and cellular telephones. To
- accomplish this, the expectation of privacy test was
- eliminated.[20]
- As amended, Title III still outlaws the electronic
- interception of communications. The word "communications"
- indicates that someone is attempting to communicate
- something to someone; it does not refer to the inadvertent
- transmission of information. The reception and
- reconstruction of emanated transient electromagnetic pulses
- (ETEP), however, is based on obtaining information that the
- target does not mean to transmit. If the ETEP is not
- intended as communication, and is therefore not transmitted
- in a form approaching current communications protocols, then
- it can not be considered communications as contemplated by
- Congress when it amended Title III. Reception, or
- interception, of emanated transient electromagnetic pulses
- is not criminalized by Title III as amended.
-
- III. ENGLISH LAW
- In England the Interception of Communications Act
- 1985[21] criminalizes the tapping of communications sent over
-
- _____________________
-
- 17. United States v. Hall, 488 F.2d 193 (9th Cir. 1973) (found
- no legislative history indicating Congress intended the act to
- include radio-telephone conversations). Further, Title III only
- criminalized the interception of "aural" communications which
- excluded all forms of computer communications.
-
- 18. Willamette Subscription Television v. Cawood, 580 F.Supp
- 1164 (D. Or. 1984) (non-wire communications lacks any expectation
- of privacy).
-
- 19. Pub. L. No. 99-508, 100 Stat. 1848 (codified at 18 U.S.C.
- 2510-710) [hereinafter ECPA].
-
- 20. 18 U.S.C. 2511(1)(a) criminalizes the interception of "any
- wire, oral or electronic communication" without regard to an
- expectation of privacy.
-
- 21. Interception of Communications Act 1985, Long Title, An Act
- to make new provision for and in connection with the interception
- of communications sent by post or by means of public
- telecommunications systems and to amend section 45 of the
- Telecommunications Act 1984.
-
- <New Page>
- public telecommunications lines.[22] The interception of
- communications on a telecommunication line can take place
- with a physical tap on the line, or the passive interception
- of microwave or satellite links.[23] These forms of passive
- interception differ from TEMPEST ELINT because they are
- intercepting intended communication; TEMPEST ELINT
- intercepts unintended communication. Eavesdropping on the
- emanations of computers does not in any way comport to
- tapping a telecommunication line and therefore falls outside
- the scope of the statute.[24]
-
- IV. CANADIAN LAW
- Canada has taken direct steps to limit eavesdropping on
- computers. The Canadian Criminal Amendment Act of 1985
-
- _____________________
-
- 22. Interception of Communications Act 1985 1, Prohibition on
- Interception:
- (1) Subject to the following provisions of this section, a
- person who intentionally intercepts a communication in the
- course of its transmission by post or by means of a public
- telecommunications system shall be guilty of an offence and
- liable--
- (a) on summary conviction, to a fine not exceeding the
- statutory maximum;
- (b) on conviction on indictment, to imprisonment for a
- term not exceeding two years or to a fine or to both.
- ***
-
- 23. Tapping (aka trespassatory eavesdropping) is patently in
- violation of the statute. "The offense created by section 1 of
- the Interception of Communications Act 1985 covers those forms of
- eavesdropping on computer communications which involve "tapping"
- the wires along which messages are being passed. One problem
- which may arise, however, is the question of whether the
- communication in question was intercepted in the course of its
- transmission by means of a public telecommunications system. It
- is technically possible to intercept a communication at several
- stages in its transmission, and it may be a question of fact to
- decide the stage at which it enters the "public" realm. THE LAW
- COMMISSION,WORKING PAPER NO. 110: COMPUTER MISUSE, 3.30 (1988).
-
- 24. "There are also forms of eavesdropping which the Act does
- not cover. For example. eavesdropping on a V.D.U. [referred to
- in this text as a CRT] screen by monitoring the radiation field
- which surrounds it in order to display whatever appears on the
- legitimate user's screen on the eavesdropper's screen. This
- activity would not seem to constitute any criminal offence..."
- THE LAW COMMISSION, WORKING PAPER NO. 110: COMPUTER MISUSE, 3.31
- (1988).
-
- <New Page>
- criminalized indirect access to a computer service.[25] The
- specific reference to an "electromagnetic device" clearly
- shows the intent of the legislature to include the use of
- TEMPEST ELINT equipment within the ambit of the legislation.
- The limitation of obtaining "any computer service" does
- lead to some confusion. The Canadian legislature has not
- made it clear whether "computer service" refers to a
- computer service bureau or merely the services of a
- computer. If the Canadians had meant access to any
- computer, why did they refer to any "computer service".
- This is especially confusing considering the al-
- encompassing language of (b) 'any function of a computer
- system'.
- Even if the Canadian legislation criminalizes
- eavesdropping on all computers, it does not solve the
- problem of protecting the privacy of information. The
- purpose of criminal law is to control crime.[26] Merely
- making TEMPEST ELINT illegal will not control its use.
- First, because it is an inherently passive crime it is
- impossible to detect and hence punish. Second, making this
- form of eavesdropping illegal without taking a proactive
- stance in controlling compromising emanations gives the
- public a false sense of security. Third, criminalizing the
- possession of a TEMPEST ELINT device prevents public sector
- research into countermeasures. Finally, the law will not
- prevent eavesdropping on private information held in company
- computers unless disincentives are given for companies that
- do not take sufficient precautions against eavesdropping and
- simple, more common, information crimes.[27]
- _____________________
-
- 25. 301.2(1) of the Canadian criminal code states that anyone
- who:
-
- ... without color of right,
- (a) obtains, directly or indirectly, any computer service,
- (b) by means of an electromagnetic ... or other device,
- intercepts or causes to be intercepted, either directly or
- indirectly, any function of a computer system ... [is guilty of
- an indictable offence].
-
- 26. UNITED STATES SENTENCING COMM'N, FEDERAL SENTENCING
- GUIDELINES MANUAL (1988) (Principles Governing the Redrafting of
- the Preliminary Guidelines "g." (at an unknown page))
-
- 27. There has been great debate over what exactly is a computer
- crime. There are several schools of thought. The more
- articulate school, and the one to which the author adheres holds
- that the category computer crime should be limited to crimes
- directed against computers; for example, a terrorist destroying a
- computer with explosives would fall into this category. Crimes
- such as putting ghost employees on a payroll computer and
-
- <New Page>
-
- V. SOLUTIONS
- TEMPEST ELINT is passive. The computer or terminal
- emanates compromising radiation which is intercepted by the
- TEMPEST device and reconstructed into useful information.
- Unlike conventional ELINT there is no need to physically
- trespass or even come near the target. Eavesdropping can be
- performed from a nearby office or even a van parked within a
- reasonable distance. This means that there is no classic
- scene of the crime; and little or no chance of the criminal
- being discovered in the act.[28]
- If the crime is discovered it will be ancillary to some
- other investigation. For example, if an individual is
- investigated for insider trading a search of his residence
- may yield a TEMPEST ELINT device. The device would explain
- how the defendant was obtaining insider information; but it
- was the insider trading, not the device, that gave away the
- crime.
- This is especially true for illegal TEMPEST ELINT
- performed by the state. Unless the perpetrators are caught
- in the act there is little evidence of their spying. A
- trespassatory bug can be detected and located; further, once
- found it provides tangible evidence that a crime took place.
- A TEMPEST ELINT device by its inherent passive nature leaves
- nothing to detect. Since the government is less likely to
- commit an ancillary crime which might be detected there is a
- very small chance that the spying will ever be discovered.
- The only way to prevent eavesdropping is to encourage the
- use of countermeasures: TEMPEST Certified[29] computers and
- _____________________
-
- collecting their pay are merely age-old accounting frauds; today
- the fraud involves a computer because the records are kept on a
- computer. The computer is merely ancillary to the crime. This
- has been mislabeled computer crime and should merely be referred
- to as a fraud perpetrated with the aid of a computer. Finally,
- there are information crimes. These are crimes related to the
- purloining or alteration of information. These crimes are more
- common and more profitable due to the computer's ability to hold
- and access great amounts of information. TEMPEST ELINT can best
- be categorized as a information crime.
-
- 28. Compare, for example, the Watergate breakin in which the
- burglars were discovered when they returned to move a poorly
- placed spread spectrum bug.
-
- 29. TEMPEST Certified refers to the equipment having passed a
- testing and emanations regime specified in NACSIM 5100A. This
- classified document sets forth the emanations levels that the NSA
- believes digital equipment can give off without compromising the
- information it is processing. TEMPEST Certified equipment is
- theoretically secure against TEMPEST eavesdropping.
-
- <New Page>
- terminals.
- In merely making TEMPEST ELINT illegal the public is
- given the false impression of security; they lulled into
- believing the problem has been solved. Making certain
- actions illegal does not prevent them from occurring. This
- is especially true for a TEMPEST ELINT because it is
- undetectable. Punishment is an empty threat if there is no
- chance of being detected; without detection there can be no
- apprehension and conviction. The only way to prevent some
- entity from eavesdropping on one's computer or computer
- terminal is for the equipment not to give off compromising
- emanation; it must be TEMPEST Certified.
- The United States can solve this problem by taking a
- proactive stance on compromising emanations. The National
- Institute of Standards and Technology (NIST[30]) is in charge
- of setting forth standards of computer security for the
- private sector. NIST is also charged with doing basic
- research to advance the art of computer security. Currently
- NIST does not discuss TEMPEST with the private sector. For
- privacy's sake, this policy must be changed to a proactive
- one. The NIST should publicize the TEMPEST ELINT threat to
- computer security and should set up a rating system for
- level of emanations produced by computer equipment.[31]
- Further, legislation should be enacted to require the
- labeling of all computer equipment with its level of
- emanations and whether it is TEMPEST Certified. Only if the
- public knows of the problem can it begin to take steps to
- solve it.
- Title III makes possession of a surveillance device a
- crime, unless it is produced under contract to the
- government. This means that research into surveillance and
- counter-surveillance equipment is monopolized by the
- government and a few companies working under contract with
- _____________________
-
- NACSIM 5100A is classified, as are all details of TEMPEST.
- To obtain access to it, contractor must prove that there is
- demand within the government for the specific type of equipment
- that intend to certify. Since the standard is classified, the
- contractors can not sell the equipment to non-secure governmental
- agencies or the public. This prevents reverse engineering of the
- standard for its physical embodiment, the Certified equipment.
- By preventing the private sector from owning this anti-
- eavesdropping equipment, the NSA has effectively prevented the
- them from protecting the information in their computers.
-
- 30. Previously the Bureau of Standards. The NIST is a division
- of the Commerce Department.
-
- 31. In this case computer equipment would include all peripheral
- computer equipment. There is no use is using a TEMPEST Certified
- computer if the printer or the modem are not Certified.
-
- <New Page>
- the government. If TEMPEST eavesdropping is criminalized,
- then possession of TEMPEST ELINT equipment will be criminal.
- Unfortunately,this does not solve the problem. Simple
- TEMPEST ELINT equipment is easy to make. For just a few
- dollars many older television sets can be modified to
- receive and reconstruct EMR. For less than a hundred
- dollars a more sophisticated TEMPEST ELINT receiver can be
- produced[32].
- The problem with criminalizing the possession of
- TEMPEST ELINT equipment is not just that the law will have
- little effect on the use of such equipment, but that it will
- have a negative effect on counter-measures research. To
- successfully design counter-measures to a particular
- surveillance technique it is vital to have a complete
- empirical understanding of how that technique works.
- Without the right to legally manufacture a surveillance
- device there is no possible way for a researcher to have the
- knowledge to produce an effective counter-measures device.
- It is axiomatic: without a surveillance device, it is
- impossible to test a counter-measures device.
- A number of companies produce devices to measure the
- emanations from electrical equipment. Some of these devices
- are specifically designed for bench marking TEMPEST
- Certified equipment. This does not solve the problem. The
- question arises: how much radiation at a particular
- frequency is compromising? The current answer is to refer
- _____________________
-
- 32. The NSA has tried to limit the availability of TEMPEST
- information to prevent the spread of the devices.
- For a discussion of the First Amendment and prior restraint
- See, e.g. The United States of America v. Progressive, Inc. 467
- F.Supp 990 (1979, WD Wis.)(magazine intended to publish plans for
- nuclear weapon; prior restraint injunction issued), reh. den.
- United States v. Progressive Inc. 486 F.Supp 5 (1979, WD Wis.),
- motion den Morland v. Sprecher 443 US 709 (1979)(mandamus),
- motion denied United States v. Progressive, Inc. 5 Media L R
- (1979, 7th Cir.), dismd. without op. U.S. v. Progressive, Inc 610
- F.2d 819 (1979, 7th Cir.); New York Times, Co. v. United States,
- 403 U.S. 713 (1971)(per curium)(Pentagon Papers case: setting
- forth prior restraint standard which government was unable to
- meet); T. EMERSON, THE SYSTEM OF FREEDOM OF EXPRESSION (1970);
- Balance Between Scientific Freedom and NAtional Security, 23
- JURIMETRICS J. 1 (1982)(current laws and regulations limiting
- scientific and technical expression exceed the legitimate needs
- of national security); Hon. M. Feldman, Why the First Amendment
- is not Incompatible with National Security, HERITAGE FOUNDATION
- REPORTS (Jan. 14, 1987). Compare Bork, Neutral Principles and
- Some First Amendment Problems, 47 IND. L. J. 1 (First Amendment
- applies only to political speech); G. Lewy, Can Democracy Keep
- Secrets, 26 POLICY REVIEW 17 (1983)(endorsing draconian secrecy
- laws mirroring the English system).
-
- <New Page>
- to NACSIM 5100A. This document specifies the emanations
- levels suitable for Certification. The document is only
- available to United States contractors having sufficient
- security clearance and an ongoing contract to produce
- TEMPEST Certified computers for the government. Further,
- the correct levels are specified by the NSA and there is no
- assurance that, while these levels are sufficient to prevent
- eavesdropping by unfriendly operatives, equipment certified
- under NACSIM 5100A will have levels low enough to prevent
- eavesdropping by the NSA itself.
- The accessibility of supposedly correct emanations
- levels does not solve the problem of preventing TEMPEST
- eavesdropping. Access to NACSIM 5100A limits the
- manufacturer to selling the equipment only to United States
- governmental agencies with the need to process secret
- information.[33] Without the right to possess TEMPEST ELINT
- equipment manufacturers who wish to sell to the public
- sector cannot determine what a safe level of emanations is.
- Further those manufacturers with access to NACSIM 5100A
- should want to verify that the levels set out in the
- document are, in fact, low enough to prevent interception.
- Without an actual eavesdropping device with which to test,
- no manufacturer will be able to produce genuinely
- uncompromising equipment.
-
- Even if the laws allow ownership of TEMPEST Certified
- equipment by the public, and even if the public is informed
- of TEMPEST's threat to privacy, individuals' private
- information will not necessarily by protected. Individuals
- may choose to protect their own information on their own
- computers. Companies may choose whether to protect their
- own private information. But companies that hold the
- private information of individuals must be forced to take
- steps to protect that information.
- In England the Data Protection Act 1984[34] imposes
- sanctions against anyone who stores the personal
- information[35] on a computer and fails to take reasonable
- _____________________
-
- 33. For example, the NSA has just recently allowed the Drug
- Enforcement Agency (DEA) to purchase TEMPEST Certified computer
- equipment. The DEA wanted secure computer equipment because
- wealthy drug lords had were using TEMPEST eavesdropping
- equipment.
-
- 34. An Act to regulate the use of automatically processed
- information relating to individuals and the provision of services
- in respect of such information.
- -Data Protection Act 1984, Long Title.
-
- 35. "Personal data" means data consisting of information which
- relates to a living individual who can be identified from that
-
- <New Page>
- measures to prevent disclosure of that information. The act
- mandates that personal data may not be stored in any
- computer unless the computer bureau or data user[36] has
- registered under the act.[37] This provides for a central
- registry and the tracking of which companies or persons
- maintain databases of personal information. Data users and
- bureaux must demonstrate a need and purpose behind their
- possession of personal data.
- The act provides tort remedies to any person who is
- damaged by disclosure of the personal data.[38] Reasonable
- care to prevent the disclosure is a defense.[39] English
- _____________________
-
- information (or from that and other information in the possession
- of the data user), including any expression of opinion about the
- individual but not any indication of the intentions of the data
- user in respect of that individual.
- -Data Protection Act 1984 1(3)
-
- 36. "Data user" means a person who holds data, and a persons
- "Holds" data if --
- (a) the data form part of a collection of data processed or
- intended to be processed by or on behalf of that person as
- mentioned in subsection (2) above; [subsection (2) defines
- "data"] and
- (b) that person (either alone or jointly or in common with
- other persons) controls the contents and use of the data
- comprised in the collection; and
- (c) the data are in the form in which they have been or are
- intended to be processed as mentioned in paragraph (a) above
- or (though not for the time being in that form) in a form
- into which they have been converted after being so processed
- and with a view to being further so processed on a
- subsequent occasion.
- - Data Protection Act 1(5).
-
- 37. Data Protection Act 1984, 4,5.
-
- 38. An individual who is the subject of personal data held by a
- data user... and who suffers damage by reason of (1)(c) ... the
- disclosure of the data, or access having been obtained to the
- data without such authority as aforesaid shall be entitled to
- compensation from the data user... for any distress which the
- individual has suffered by reason of the ... disclosure or
- access.
- - Data Protection Act 1984 23.
-
- 39. ... it shall be a defense to prove that ... the data user
- ... had taken such care as in all the circumstances was
- reasonably required to prevent the... disclosure or access in
- question.
- Data Protection Act 1984 23(3)
-
- <New Page>
- courts have not yet ruled what level of computer security
- measures constitute reasonable care. Considering the
- magnitude of invasion possible with TEMPEST ELINT it should
- be clear by now that failure to use TEMPEST Certified
- equipment is prima facie unreasonable care.
- The Remedies section of the act provides incentive for
- these entities to provide successful protection of person
- data from disclosure or illicit access. Failure to protect
- the data will result in monetary loss. This may be looked
- at from the economic efficiency viewpoint as allocating the
- cost of disclosure the persons most able to bear those
- costs, and also most able to prevent disclosure. Data users
- that store personal data would use TEMPEST Certified
- equipment as part of their computer security plan, thwarting
- would-be eavesdroppers.
- The Data Protection Act 1984 allocates risk to those
- who can bear it best and provides an incentive for them to
- keep other individuals' data private. This act should be
- adopted by the United States as part of a full-spectrum plan
- to combat TEMPEST eavesdropping. Data users are in the best
- position to prevent disclosure through proper computer
- security. Only by making them liable for failures in
- security can we begin to rein in TEMPEST ELINT.
-
- VII
- Recommendations
- Do not criminalize TEMPEST ELINT. Most crimes that
- TEMPEST ELINT would aid, such a insider trading, are already
- illegal; the current laws are adequate.
- The National Institute of Standards and Technology
- should immediately begin a program to educate the private
- sector about TEMPEST. Only if individuals are aware of the
- threat can they take appropriate precautions or decide
- whether any precautions are necessary.
- Legislation should be enacted to require all
- electronic equipment to prominently display its level of
- emanations and whether it is TEMPEST Certified. If
- individuals are to choose to protect themselves they must be
- able to make a informed decision regarding how much
- protection is enough.
- TEMPEST Certified equipment should be available to
- the private sector. The current ban on selling to non-
- governmental agencies prevents individuals who need to
- protect information from having the technology to do so.
- Possession of TEMPEST ELINT equipment should not be
- made illegal. The inherently passive nature and simple
- design of TEMPEST ELINT equipment means that making its
- possession illegal will not deter crime; the units can be
- easily manufactured and are impossible to detect. Limiting
- their availability serves only to monopolize the
- countermeasures research, information, and equipment for the
- government; this prevents the testing, design and
-
- <New Page>
- manufacture of counter-measures by the private sector.
- Legislation mirroring England's Data Protection Act
- 1984 should be enacted. Preventing disclosure of personal
- data can only be accomplished by giving those companies
- holding the data a reason to protect it. If data users are
- held liable for their failure to take reasonable security
- precautions they will begin to take reasonable security
- precautions, including the use of TEMPEST Certified
- equipment.
-