Satellite phone calls could soon be easy to listen in on.
Every day you pick up your mobile phone and gab away -ââ,¬" for business calls, to arrange your personal schedule, or just to chat. You don't think about security much, and you probably use the phone to conduct sensitive business or to give out financial information like credit card numbers when you shop. But your mobile phone calls, and now your satellite phone calls, may not be as private as you think.
Organisations that advocate strong privacy enforcement, such as the US-based EPIC (Electronic Privacy Information Center) and the American Civil Liberties Union, have fought for years to allow personal use of encryption technology. They also battle against legislation that would expand the power of agencies like the US National Security Agency to monitor phone transmissions, e-mail, and Internet usage. The US government argues that criminals will take advantage of privacy laws unless government agents can access any data sent through digital channels, and it insists that giving strong encryption to everyone will cripple efforts to curb terrorism.
But both sides agree that because information has gone digital, and the use of such technologies as fibre-optic cable, spread-spectrum wireless phones, and cryptography have become more common, government agents have had a harder time intercepting and scanning all the bits of data that fly around every day. Satellite phone calls have been particularly difficult to eavesdrop on.
But even the Echelon program ââ,¬"- supposedly a joint effort of American, British, Australian and other governments that globally scans all unencrypted ground and radio transmissions for certain keywords -ââ,¬" can't decipher encrypted transmissions, and it has trouble with transmissions over all but traditional wired lines. Until recently, direct satellite-to-satellite transmissions, which never travel through ground wires, have been among the most difficult to intercept.
Land lines, like those used by an ordinary household phone, are easy to scan with the proper tools. But because satellite transmissions don't pass through a ground wire, the only way to tap in was to reroute the signal to a ground wire where it could be read. This diversion had the effect of degrading transmission quality so much that the interception was noticeable.
A recent patent application by Motorola describes a new technology that diverts satellite transmission imperceptibly because it does not degrade the signal. This technology can copy any satellite transmission so the original never has to travel over a ground wire. Only the copy goes through the ground wire to be recorded.
The interception uses a key to bounce the signal to the ground briefly. The people or computers on both ends of the call have no idea that their transmission has been compromised.
Mike Mattera, an engineer at Motorola and the inventor of the technology, says he developed this capability for the now-defunct Iridium satellite system because US law mandated it. "You would have to have had a court order to use the key," he says, "and the system could only handle a few interceptions at a time." Mattera asserts that the Motorola technology "could never be used for wholesale scanning" such as Echelon is believed to provide.
Still, unless you have access to the court records you won't know for sure who the government is listening to. We have no way of knowing whether programs like Echelon exist and whether they are scanning all, none, or only some portion of our phone calls. Intercepting calls was designed to be unobtrusive -- so someone could monitor you, and you'd never notice.
