Forwarded from: William Knowles <wkat_private> http://www.nandotimes.com/technology/story/559741p-4408024c.html By JIM KRANE, AP Technology Writer NEW YORK (October 2, 2002 6:10 p.m. EDT) - Satellites are increasingly relied upon for military and intelligence use but securely transmitting voice, image and other communications remains troublesome. In June, for instance, European satellite TV viewers could watch surveillance video of American military bases in Bosnia that was being broadcast in an unencrypted stream, via satellite. Now, British military researchers have improved an emerging method of secure transmission for the encryption keys used to unscramble such data. In a demonstration reported in this week's issue of the journal Nature, the researchers say they successfully exchanged encryption keys transmitted on a beam of invisible light. The researchers completed the exchange from the summits of mountaintops in southern Germany that are 14 miles apart. Within seven years, the technique ought to be able to transmit encryption keys to any receiving point on the planet, via low-orbiting satellite, said John Rarity, a scientist with QinetiQ, the commercial arm of Britain's defense research lab. Current encryption technology uses mathematical "keys" that are exchanged between trusting users. The keys are used to unscramble messages, video and other data. Such keys, made of random strings of digits, can be intercepted on conventional networks. So they are routinely sent by less efficient means. "At the moment, highly secure encryption keys are typically sent by a man on a motorbike or a guy with a diplomatic bag," Rarity said. Rarity and other researchers believe keys can be more reliably exchanged using methods of physics, rather than mathematics. QinetiQ's experiment involved attaching the key's digits to individual light particles, or photons, which are sent as a weak beam of light. The practice is believed to be safe because intercepting and reading the key noticeably alters the state of the photons, tipping off the intended recipient that the key has been compromised. QinetiQ isn't the only group researching the concept. Rarity said his team and a similar outfit at the U.S. Department of Energy's lab at Los Alamos, N.M., have been leapfrogging each other in the distances they've been able to send and receive their encryption key-toting light beams. Fourteen miles is the longest-yet transmission, he said. Only the keys used to unscramble the data must be sent via the light beams. The actual data could be sent in scrambled form via satellite or any sort of conveyance, Rarity said. "Once you've got your key, you can use your mobile phone or any other method," he said. In order to send light streams to low-orbiting satellites, Rarity said scientists need to improve the system's tolerance to loss of some of the data-carrying light particles, which "leak" in increasing amounts the farther the beam travels. No current satellite can handle such transmissions. Rarity said the practice, known as "quantum cryptography," would require construction and launch of new satellites. *==============================================================* "Communications without intelligence is noise; Intelligence without communications is irrelevant." Gen Alfred. M. Gray, USMC ================================================================ C4I.org - Computer Security, & Intelligence - http://www.c4i.org *==============================================================* - ISN is currently hosted by Attrition.org To unsubscribe email majordomoat_private with 'unsubscribe isn' in the BODY of the mail.
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