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Tempest Tech II

Intell IT



Be not afeard; the isle is full of noises, Sounds and sweet airs, that give delight and hurt not. Sometimes a thousand twangling instruments Will hum about mine ears, and sometime voices That, if I then had waked after long sleep, Will make me sleep again....Shakespeare The Tempest, Act III, Scene 2

One of our tech-savvy friends responded thoughtfully to our comment on the Tempest eavesdropping technology. The individual described how, late in the last century, his team had installed TEMPEST eavesdropping equipment near his agency's building. "The results were that we could read email and other information from 10-plus systems from the street outside the building. The coax Ethernet cables were bleeding so badly it must have been a heyday for espionage."

As a result of that experience, our friend the tech manager added encryption for system messages in his own system and added shielded coaxial cable to main routing lines at the agency and its various offices.

The tech specialist suggests that many federal facilities have not installed shielded coax to prevent signal leakage. As a result, the unshielded coax lines "can still be read by someone placing a retransmitter next to an open line in a corridor or closet where Ethernet lines are connected to a router or bridge device." Our friend notes that the intercepted data can be broadcast to a PC for exploitation.

However, the march of technology helps suppress the coaxial cable TEMPEST vulnerability as well, according to our tech-savvy friend. The progressive installation of optical fiber lines to replace coax wiring helps prevent this type of eavesdropping. The fiber optic lines contain hundreds of glass strands. Eavesdropping on fiber optic lines can get very expensive. Sometimes, faced with that kind of problem, intelligence agencies could find cheaper results from the low-tech "three Bs": burglary, blackmail and bribery.

Editor's note: out of an overabundance of caution, we have omitted some technical details in this item.

Posted by Wilson P. Dizard III on May 28, 2008 at 9:39 AM


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