1119 lines
45 KiB
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1119 lines
45 KiB
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Eavesdropping On the Electromagnetic Emanations of
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Digital Equipment: The Laws of Canada, England and
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the United States
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Copyright (C) 1989 By Christopher Seline
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This document is a rough draft. The Legal Sections
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are overviews. They will be significantly
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expanded in the next version.
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We in this country, in this generation, are -- by
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destiny rather than choice -- the watchmen on the
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walls of world freedom.1
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-President John F. Kennedy
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In the novel 1984, George Orwell foretold a future where
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individuals had no expectation of privacy because the state
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monopolized the technology of spying. The government
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watched the actions of its subjects from birth to death. No
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one could protect himself because surveillance and counter-
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surveillance technology was controlled by the government.
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This note explores the legal status of a surveillance
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technology ruefully known as TEMPEST2. Using TEMPEST
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technology the information in any digital device may be
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intercepted and reconstructed into useful intelligence
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without the operative ever having to come near his target.
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The technology is especially useful in the interception of
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information stored in digital computers or displayed on
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computer terminals.
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_________________________
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1. Undelivered speech of President John F. Ken-
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nedy, Dallas Citizens Council (Nov. 22, 1963) 35-36.
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2. TEMPEST is an acronym for Transient Electromag-
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netic Pulse Emanation Standard. This standard sets
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forth the official views of the United States on the
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amount of electromagnetic radiation that a device may
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emit without compromising the information it is pro-
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June 7, 1990
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- 2 -
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The use of TEMPEST is not illegal under the laws of the
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United States3, or England. Canada has specific laws
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criminalizing TEMPEST eavesdropping but the laws do more to
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hinder surveillance countermeasures than to prevent TEMPEST
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surveillance. In the United States it is illegal for an
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individual to take effective counter-measures against
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TEMPEST surveillance. This leads to the conundrum that it
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is legal for individuals and the government to invade the
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privacy of others but illegal for individuals to take steps
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to protect their privacy.
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The author would like to suggest that the solution to this
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conundrum is straightforward. Information on pro-
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tecting privacy under TEMPEST should be made freely
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available; TEMPEST Certified equipment should be legally
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available; and organizations possessing private information
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should be required by law to protect that information
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through good computer security practices and the use of
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TEMPEST Certified equipment.
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Spying is divided by professionals into two main types:
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human intelligence gathering (HUMINT) and electronic
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intelligence gathering (ELINT). As the names imply, HUMINT
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relies on human operatives, and ELINT relies on
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technological operatives. In the past HUMINT was the sole
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method for collecting intelligence.4 The HUMINT operative
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would steal important papers, observe troop and weapon
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movements5, lure people into his confidences to extract
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secrets, and stand under the eavesdrip6 of houses,
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eavesdropping on the occupants.
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_________________________
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cessing. TEMPEST is a defensive standard; a device
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which conforms to this standard is referred to as TEM-
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PEST Certified.
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The United States government has refused to declassi-
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fy the acronym for devices used to intercept the
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electromagnetic information of non-TEMPEST Certified
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devices. For this note, these devices and the
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technology behind them will also be referred to
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as TEMPEST; in which case, TEMPEST stands for
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Transient Electromagnetic Pulse Surveillance Technolo-
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gy.
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The United States government refuses to release
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details regarding TEMPEST and continues an organized
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effort to censor the dissemination of information
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about it. For example the NSA succeeded in shut-
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ting down a Wang Laboratories presentation on TEM-
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PEST Certified equipment by classifying the contents
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of the speech and threatening to prosecute the
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speaker with revealing classified information. [cite
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coming].
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3. This Note will not discuses how TEMPEST re-
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June 7, 1990
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- 3 -
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As technology has progressed, tasks that once could only
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be performed by humans have been taken over by
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machines. So it has been with spying. Modern satellite
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technology allows troop and weapons movements to be observed
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with greater precision and from greater distances than a
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human spy could ever hope to accomplish. The theft of
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documents and eavesdropping on conversations may now be
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performed electronically. This means greater safety for the
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human operative, whose only involvement may be the placing
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of the initial ELINT devices. This has led to the
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ascendancy of ELINT over HUMINT because the placement and
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monitoring of ELINT devices may be performed by a technician
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who has no training in the art of spying. The gathered
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intelligence may be processed by an intelligence expert,
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perhaps thousands of miles away, with no need of field
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experience.
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ELINT has a number of other advantages over HUMINT. If a
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spy is caught his existence could embarrass his employing
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state and he could be forced into giving up the identities
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of his compatriots or other important information. By its
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very nature, a discovered ELINT device (bug) cannot give up
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any information; and the ubiquitous nature of bugs provides
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the principle state with the ability to plausibly deny
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ownership or involvement.
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_________________________
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lates to the Warrant Requirement under the United
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States Constitution. Nor will it discuss the Consti-
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tutional exclusion of foreign nationals from the War-
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rant Requirement.
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4. HUMINT has been used by the United States
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since the Revolution. "The necessity of procuring
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good intelligence is apparent & need not be further
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urged -- All that remains for me to add is, that you
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keep the whole matter as secret as possible. For
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upon Secrecy, Success depends in Most Enterprises of
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the kind, and for want of it, they are generally de-
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feated, however well planned & promising a favorable
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issue." Letter of George Washington (Jul. 26, 1777).
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5. "... I wish you to take every possible pains in
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your powers, by sending trusty persons to Staten
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Island in whom you can confide, to obtain Intelli-
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gence of the Enemy's situation & numbers -- what
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kind of Troops they are, and what Guards they have
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-- their strength & where posted." Id.
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6. Eavesdrip is an Anglo-Saxon word, and refers to
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the wide overhanging eaves used to prevent rain from
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falling close to a house's foundation. The eavesdrip
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provided "a sheltered place where one could hide to
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listen clandestinely to conversation within the
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house." W. MORRIS & M. MORRIS, MORRIS DICTIONARY OF
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WORD AND PHRASE ORIGINS, 198 (1977).
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June 7, 1990
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- 4 -
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ELINT devices fall into two broad categories:
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trespassatory and non-trespassatory. Trespassatory bugs
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require some type of trespass in order for them to function.
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A transmitter might require the physical invasion of the
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target premises for placement, or a microphone might be
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surreptitiously attached to the outside of a window. A
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telephone transmitter can be placed anywhere on the phone
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line, including at the central switch. The trespass comes
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either when it is physically attached to the phone line, or
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if it is inductive, when placed in close proximity to the
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phone line. Even microwave bugs require the placement of
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the resonator cone within the target premises.7
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Non-trespassatory ELINT devices work by receiving
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electromagnetic radiation (EMR) as it radiates through the
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aether, and do not require the placement of bugs. Methods
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include intercepting8 information transmitted by satellite,
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microwave, and radio, including mobile and cellular phone
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transmissions. This information was purposely transmitted
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with the intent that some intended person or persons would
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receive it.
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Non-trespassatory ELINT also includes the interception of
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information that was never intended to be transmitted.
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All electronic devices emit electromagnetic radiation. Some
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of the radiation, as with radio waves, is intended to
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transmit information. Much of this radiation is not
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intended to transmit information and is merely incidental to
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whatever work the target device is performing.9 This
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information can be intercepted and reconstructed into a
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coherent form. With current TEMPEST technology it is
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possible to reconstruct the contents of computer video
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display terminal (VDU) screens from up to a kilometer
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distant10; reconstructing the contents of a computer's
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memory or the contents of its mass storage devices is more
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complicated and must be performed from a closer distance.11
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The reconstruction of information via EMR, a process for
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which the United States government refuses to declassify
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either the exact technique or even its name12, is not
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limited to computers and digital devices but is applicable
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to all devices that generate electromagnetic radiation.13
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TEMPEST is especially effective against VDUs because they
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produce a very high level of EMR.14
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_________________________
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7. Pursglove, How Russian Spy Radios Work, RADIO
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ELECTRONICS, 89-91 (Jan 1962).
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8. Interception is an espionage term of art and
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should be differentiated from its more common usage.
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When information is intercepted, the interceptor as
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well as the intended recipient receive the informa-
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tion. Interception when not used as a term of art
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refers to one person receiving something intended for
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someone else; the intended recipient never receives
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what he was intended to receive.
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June 7, 1990
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- 5 -
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"[C]ables may act as an antenna to transmit
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the signals directly or even both receive the
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signals and re-emit them further away from the
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source equipment. It is possible that cables
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acting as an antenna in such a manner could
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transmit the signals much more efficiently
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than the equipment itself...A similar effect
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may occur with metal pipes such as those for
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domestic water supplies. ... If an earthing
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[(grounding)] system is not installed correctly
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such that there is a path in the circuit with
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a very high resistance (for example where paint
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prevents conduction and is acting as an insu-
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lator), then the whole earthing system could
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well act in a similar fashion to an antenna. ...
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[For a VDU] the strongest signals, or harmonics
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thereof, are usually between 60-250 MHz approx-
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imately. There have however been noticeable
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exception of extremely strong emissions in
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the television bands and at higher frequencies
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between 450-800 MHz. Potts, Emission Security,
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3 COMPUTER LAW AND SECURITY REPORT 27 (1988).
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_________________________
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9. There are two types of emissions, conducted and
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radiated. Radiated emissions are formed when com-
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ponents or cables act as antennas for transmit the
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EMR; when radiation is conducted along cables or other
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connections but not radiated it is referred to as "con-
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ducted". Sources include cables, the ground loop,
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printed circuit boards, internal wires, the power
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supply to power line
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10. The TEMPEST ELINT operator can distinguish between
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different VDUs in the same room because of
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the different EMR characteristics of both homo and
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heterogeneous units. "[T]here is little comparison
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between EMR characteristics from otherwise comparable
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equipment. Only if the [VDU] was made with exactly
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the same components is there any similarity. If
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some of the components have come from a different
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batch, have been updated in some way, and especial-
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ly if they are from a different manufacturer,
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then completely different results are obtained. In
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this way a different mark or version of the same [VDU]
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will emit different signals. Additionally because
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of the variation of manufacturing standards between
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counties, two [VDUs] made by the same company but
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sourced from different counties will have entirely
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different EMR signal characteristics...From this it way
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be thought that there is such a jumble of emissions
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around, that it would not be possible to isolate those
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from any one particular source. Again, this is not the
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case. Most received signals have a different line
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June 7, 1990
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- 6 -
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ELINT is not limited to governments. It is routinely used
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by individuals for their own purposes. Almost all
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forms of ELINT are available to the individual with either
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the technological expertise or the money to hire someone
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_________________________
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synchronization, due to design, reflection, in-
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terference or variation of component tolerances. So
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that if for instance there are three different
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signals on the same frequency ... by fine tuning
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of the RF receiver, antenna manipulation and
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modification of line synchronization, it is possi-
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ble to lock onto each of the three signals separately
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and so read the screen information. By similar
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techniques, it is entirely possible to discriminate
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between individual items of equipment in the same
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room." Potts, supra note 9. For a discussion of
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the TEMPEST ELINT threat See e.g., Memory Bank,
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AMERICAN BANKER 20 (Apr 1 1985); Emissions from Bank
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Computer Systems Make Eavesdropping Easy, Expert
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Says, AMERICAN BANKER 1 (Mar 26 1985); CRT spying:
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a threat to corporate security, PC WEEK (Mar 10
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1987).
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11. TEMPEST is concerned with the transient elec-
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tromagnetic pulses formed by digital equipment. All
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electronic equipment radiates EMR which may be
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reconstructed. Digital equipment processes informa-
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tion as 1's and 0's--on's or off's. Because of this,
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digital equipment gives off pulses of EMR. These
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pulses are easier to reconstruct at a distance than
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the non-pulse EMR given off by analog equipment.
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For a thorough discussion the radiation problems of
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broadband digital information see e.g. military
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standard MIL-STD-461 REO2; White supra note 9,
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10.2.
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12. See supra note 2.
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13. Of special interest to ELINT collectors are
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EMR from computers, communications centers and
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avionics. Schultz, Defeating Ivan with TEMPEST, DE-
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FENSE ELECTRONICS 64 (June 1983).
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14. The picture on a CRT screen is built up
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of picture elements (pixels) organized in lines
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across the screen. The pixels are made of materi-
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al that fluoresces when struck with energy. The en-
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ergy is produced by a beam of electrons fired from an
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electron gun in the back of the picture tube. The
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electron beam scans the screen of the CRT in a regular
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repetitive manner. When the voltage of the beam is
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high then the pixel it is focused upon emits photons
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and appears as a dot on the screen. By selective-
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ly firing the gun as it scans across the face of
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the CRT, the pixels form characters on the CRT screen.
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The pixels glow for only a very short time
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and must be routinely struck by the electron beam to
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stay lit. To maintain the light output of all the
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June 7, 1990
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- 7 -
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with the expertise. Governments have attempted to
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criminalize all use of ELINT by their subjects--to protect
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the privacy of both the government and the population.
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In the United States, Title III of the Omnibus Streets and
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Crimes Act of 196815 criminalizes trespassatory ELINT as the
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intentional interception of wire communications.16 As ori-
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ginally passed, Title III did not prohibit non-
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trespassatory ELINT,17 because courts found that non-wire
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communication lacked any expectation of p2IIIrivacy.18 The
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Electronic Communications Privacy Act of 198619 amended
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Title III to include non-wire communication. ECPA was
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specifically designed to include electronic mail, inter-
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computer communications, and cellular telephones. To
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accomplish this, the expectation of privacy test was
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eliminated.20
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_________________________
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pixels that are supposed to be lit, the electron beam
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traverses the entire CRT screen sixty times a second.
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Every time the beam fires it causes a high voltage
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EMR emission. This EMR can be used to reconstruct
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the contents of the target CRT screen. TEMPEST
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ELINT equipment designed to reconstruct the informa-
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tion synchronizes its CRT with the target CRT. First,
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it uses the EMR to synchronize its electron gun with
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the electron gun in the target CRT. Then, when the
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TEMPEST ELINT unit detects EMR indicating that the tar-
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get CRT fired on a pixel, the TEMPEST ELINT unit fires
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the electron gun of its CRT. The ELINT CRT is in
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perfect synchronism with the target CRT; when the tar-
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get lights a pixel, a corresponding pixel on the TEM-
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PEST ELINT CRT is lit. The exact picture on the tar-
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get CRT will appear on the TEMPEST ELINT CRT. Any
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changes on the target screen will be instantly re-
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flected in the TEMPEST ELINT screen.
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TEMPEST Certified equipment gives off emissions
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levels that are too faint to be readily detected.
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Certification levels are set out in National
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Communications Security Information Memorandum
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5100A (NACSIM 5100A). "[E]mission levels are
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expressed in the time and frequency domain, broadband
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or narrow band in terms of the frequency domain, and
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in terms of conducted or radiated emissions." White,
|
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supra, note 9, 10.1.
|
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For a thorough though purposely misleading dis-
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cussion of TEMPEST ELINT see Van Eck, Electromagnetic
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Radiation from Video Display units: An Eavesdropping
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Risk?, 4 Computers & Security 269 (1985).
|
||
15. Pub. L. No. 90-351, 82 Stat. 197. The Act
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criminalizes trespassatory ELINT by individuals as
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well as governmental agents. cf. Katz v. United
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States, 389 U.S. 347 (1967) (Fourth Amendment prohibits
|
||
surveillance by government not individuals.)
|
||
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|
||
June 7, 1990
|
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- 8 -
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As amended, Title III still outlaws the electronic
|
||
interception of communications. The word "communications"
|
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indicates that someone is attempting to communicate
|
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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.
|
||
|
||
In England the Interception of Communications Act
|
||
198521 criminalizes the tapping of communications sent over
|
||
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
|
||
_________________________
|
||
16. 18 U.S.C. 2511(1)(a).
|
||
17. United States v. Hall, 488 F.2d 193 (9th Cir.
|
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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 ex-
|
||
cluded 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].
|
||
9 20. 18 U.S.C. 2511(1)(a) criminalizes the
|
||
interception of "any wire, oral or electronic com-
|
||
munication" without regard to an expectation of
|
||
privacy.
|
||
21. Interception of Communications Act 1985, Long Ti-
|
||
tle, 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 Telecom-
|
||
munications Act 1984.
|
||
22. Interception of Communications Act 1985 1,
|
||
Prohibition on Interception:
|
||
(1) Subject to the following provisions of this sec-
|
||
tion, a person who intentionally intercepts a com-
|
||
|
||
|
||
9 June 7, 1990
|
||
|
||
|
||
|
||
|
||
|
||
- 9 -
|
||
|
||
|
||
Canada has taken direct steps to limit eavesdropping on com-
|
||
puters. The Canadian Criminal Amendment Act of 1985
|
||
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 com-
|
||
puter 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
|
||
_________________________
|
||
munication 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 Communica-
|
||
tions 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 inter-
|
||
cepted 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).
|
||
|
||
|
||
|
||
|
||
June 7, 1990
|
||
|
||
|
||
|
||
|
||
|
||
- 10 -
|
||
|
||
|
||
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
|
||
|
||
|
||
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
|
||
_________________________
|
||
25. 301.2(1) of the Canadian criminal code states
|
||
that anyone who without color of right,
|
||
(a) obtains, directly or indirectly, any computer ser-
|
||
vice,
|
||
(b) by means of an electromagnetic ... or oth-
|
||
er device, intercepts or causes to be intercept-
|
||
ed, either directly or indirectly, any function of a
|
||
computer system ... [is guilty of an indictable of-
|
||
fence].
|
||
26. UNITED STATES SENTENCING COMM'N, FEDERAL
|
||
SENTENCING GUIDELINES MANUAL (1988) (Principles Govern-
|
||
ing 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 com-
|
||
puter 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 collecting their pay are
|
||
merely age-old accounting frauds; today the fraud in-
|
||
volves 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 infor-
|
||
mation crimes. These are crimes related to the pur-
|
||
loining 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.
|
||
|
||
|
||
|
||
|
||
June 7, 1990
|
||
|
||
|
||
|
||
|
||
|
||
- 11 -
|
||
|
||
|
||
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 per-
|
||
formed by the state. Unless the perpetrators are caught in
|
||
the act there is little evidence of their spying. A
|
||
trespatory 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 Certified29 computers and
|
||
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.
|
||
_________________________
|
||
28. Compare, for example, the Watergate breakin in
|
||
which the burglars were discovered when they re-
|
||
turned 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 equip-
|
||
ment can give off without compromising the information
|
||
it is processing. TEMPEST Certified equipment is
|
||
theoretically secure against TEMPEST eavesdropping.
|
||
NACSIM 5100A is classified, as are all details
|
||
of TEMPEST. To obtain access to it, contractor
|
||
must prove that there is demand within the govern-
|
||
ment for the specific type of equipment that intend to
|
||
|
||
|
||
|
||
June 7, 1990
|
||
|
||
|
||
|
||
|
||
|
||
- 12 -
|
||
|
||
|
||
The United States can solve this problem by taking a
|
||
proactive stance on compromising emanations. The National
|
||
Institute of Standards and Technology (NIST30) 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
|
||
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
|
||
produced32.
|
||
|
||
The problem with criminalizing the possession of TEM-
|
||
PEST 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
|
||
_________________________
|
||
certify. Since the standard is classified, the con-
|
||
tractors can not sell the equipment to non-secure
|
||
governmental agencies or the public. This prevents re-
|
||
verse 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.
|
||
|
||
|
||
|
||
|
||
June 7, 1990
|
||
|
||
|
||
|
||
|
||
|
||
- 13 -
|
||
|
||
|
||
impossible to test a counter-measures device.
|
||
|
||
A number of companies produce devices to measure the ema-
|
||
nations 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
|
||
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 lev-
|
||
els 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.
|
||
|
||
|
||
_________________________
|
||
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 us-
|
||
ing a TEMPEST Certified computer if the printer or the
|
||
modem are not Certified.
|
||
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. Un-
|
||
ited 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 EXPRES-
|
||
|
||
|
||
|
||
June 7, 1990
|
||
|
||
|
||
|
||
|
||
|
||
- 14 -
|
||
|
||
|
||
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 198434 imposes
|
||
sanctions against anyone who stores the personal
|
||
information35 on a computer and fails to take reasonable
|
||
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 user36 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
|
||
_________________________
|
||
SION (1970); Balance Between Scientific Freedom and
|
||
NAtional Security, 23 JURIMETRICS J. 1
|
||
(1982)(current laws and regulations limiting scien-
|
||
tific 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).
|
||
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.
|
||
|
||
|
||
|
||
|
||
June 7, 1990
|
||
|
||
|
||
|
||
|
||
|
||
- 15 -
|
||
|
||
|
||
damaged by disclosure of the personal data.38 Reasonable
|
||
care to prevent the disclosure is a defense.39 English
|
||
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.
|
||
|
||
|
||
_________________________
|
||
35. "Personal data" means data consisting of informa-
|
||
tion which relates to a living individual who can be
|
||
identified from that information (or from that and
|
||
other information in the possession of the data user),
|
||
including any expression of opinion about the indivi-
|
||
dual 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 pro-
|
||
cessed 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 para-
|
||
graph (a) above or (though not for the time being in
|
||
that form) in a form into which they have been con-
|
||
verted after being so processed and with a view to
|
||
being further so processed on a subsequent occa-
|
||
sion.
|
||
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 rea-
|
||
son of (1)(c) ... the disclosure of the data, or ac-
|
||
cess having been obtained to the data without such
|
||
authority as aforesaid shall be entitled to compen-
|
||
sation from the data user... for any distress which
|
||
the individual has suffered by reason of the ...
|
||
|
||
|
||
|
||
June 7, 1990
|
||
|
||
|
||
|
||
|
||
|
||
- 16 -
|
||
|
||
|
||
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
|
||
|
||
|
||
|
||
- 16 -
|
||
77777777777security can we begin to rein in TEMPEST ELINT. Do not
|
||
criminalize TEMPEST ELINT. Most crimes that TEMPEST ELINT
|
||
would aid, such a insider trading, are already illegal; the
|
||
current laws are adequate.
|
||
|
||
|
||
|
||
|
||
- 16 -
|
||
777777777The 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.
|
||
|
||
|
||
|
||
|
||
- 16 -
|
||
7777777777Legislation should be enacted to require all elec-
|
||
tronic 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.
|
||
|
||
|
||
|
||
|
||
- 16 -
|
||
77777777777TEMPEST 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.
|
||
|
||
|
||
|
||
|
||
- 16 -
|
||
777777777Possession 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
|
||
manufacture of counter-measures by the private sector.
|
||
|
||
|
||
|
||
|
||
- 16 -
|
||
77777777777777Legislation mirroring England's Data Protection Act 1984
|
||
should be enacted. Preventing disclosure of personal data
|
||
can only be accomplished by giving those companies hold-
|
||
ing 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.
|
||
|
||
|
||
|
||
9 [] Respectfully submitted,
|
||
|
||
Christopher J. Seline cjs@cwru.cwru.edu
|
||
cjs@cwru.bitnet
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
9
|
||
|
||
|
||
June 7, 1990
|
||
|
||
|