In early 1981, National Security Agency officials working at an intelligence facility in suburban Washington made an alarming discovery: someone had made off with a sizable haul of classified information. The thief did not jimmy open a window at the well-guarded site; instead, he gained access to a "secure" cable leading into the facility and was able to trespass electronically. NSA officials believed the breach was the work of an East bloc spy agency.
If so, it was not the only one. A previously undisclosed series of high-tech espionage coups have been achieved by both sides. "Foreign intelligence services have gained access to classified information in U.S. computers by remote means," a former senior Government computer expert told TIME. "And we have done the same thing to them."
Last week the U.S. arrested and then expelled a Soviet military attache for allegedly trying to steal details of computer-security programs. The incident, as well as the arrest earlier this month of three West German computer hackers suspected of spying for the Soviet Union, highlighted the extent to which rival intelligence agencies are scrambling to devise ways to penetrate one another's security systems.
A number of current or former officials say U.S. intelligence agencies have had considerable success in penetrating classified military computer systems in the Soviet Union and other countries. The rule, explains one expert, is that "any country whose sensitive communications we can read, we can get into their computers." Breaches of some Soviet computers were done not by cracking codes but by physically breaking into Soviet military facilities, sources said.
Both the NSA and CIA have also "experimented" with the disruption of other nations' computers by infecting them with viruses and other destructive programs, according to some sources. But there is said to be concern in the intelligence community that these disruption operations could go too far and lead to retaliation.
The military's growing reliance on linked computer networks for battle management and command and control increases the danger of catastrophic sabotage by a hostile insider. That's why some U.S. security officials lie awake at night imagining scenarios like these:
-- An enemy agent in the Pentagon sends a computer virus through the World- Wide Military Command and Control System, which U.S. commanders would rely on in wartime for information and coordination. The virus sits undetected. When hostilities begin, the agent sends a message that triggers the virus, erasing everything in the system.
-- A different virus is introduced into NATO's logistics computers. Triggered just as the Soviet army marches into West Germany, the virus alters messages so that all allied supplies are sent to the wrong places. By the time the mistake is corrected a day or two later, key parts of NATO's defense line have collapsed.