Tapping devices could be bypassed by ''idle signal'', warns study

Tapping devices could be bypassed by ''idle signal'', warns study

Wiretapping technologies that have been commonly used by law enforcement agencies have a major security flaw that allows the subject being tapped to switch of the recorder and even mess up the numbers dialed, says a new report published in Security & Privacy, which is a flagship journal of the Institute of Electrical and Electronics Engineers.

The New York Times says that many crooks could use this to fudge up recording devices that are meant to keep tabs on them. The study into these devices was conducted by the department of computer and information science at the University of Pennsylvania.

"This has implications not only for the accuracy of the intelligence that can be obtained from these taps but also for the acceptability and weight of legal evidence derived from it," write lead author Matt Blaze and colleagues.

According to the report, any target who wishess to smudge up the recording devices should only send an "idle signal." This signal is already sent to the devices when the telephone is not being used. But a cleaver crook can send this signal called the C-tone even when he/she is merrily having a conversation. "It turns the recorder right off," said Blaze.

A FBI spokeswoman said that the agency was aware that there were some flaws in the surveillance equipment, but these flaws were present in only about 10 percent of older devices use to tap.

"We were aware of it, we dealt with it, and we believe Calea has addressed it," said Catherine Milhoan, the FBI spokeswoman. The current study into these devices is funded by the National Science Foundation's Cyber Trust program and Blaze acknowledged that he had already shared this critical information with the FBI.

He added that the agency need to do something since this flaw had the potential to "threaten law enforcement's access to the entire spectrum of intercepted communications." Blaze added that not all the tapping equipment is vulnerable. Only older systems are a victim to this flaw, but these systems continue to be used by state and law enforcement authorities.