"SECURITY: Air Force taps secure ultrawideband"

Sandia National Laboratories has combined ultrawideband (UWB) radio signals with advanced encryption techniques to develop a secure sensor and communications network for the U.S. military. The ultrasecure UWB communication system promises to help the government protect its troops on the battlefield by detecting the position of enemies and by making it much harder for them eavesdrop or jam military communications. "We are making military communications signals extremely difficult to detect, intercept or jam," said Sandia National Laboratories researcher Timothy Cooley, "by utilizing the immense spectrum of UWB to spread the energy of communications signals from sensors over such a wide frequency spectrum that the signal power falls below the noise floor of normal receivers." Cooley added, "By combining UWB with AES [Advanced Encryption Standard], our signals are virtually impossible to crack." Also known as "impulse radio," ultrawideband radio transmissions smear a wide spectrum with short, 100-picosecond pulses that are below the noise floor of conventional radio receivers. Even if enemies were equipped with a special UWB receiver, they would be unlikely to know how to reassemble the disparate data packets of each impulse into a coherent whole. And even if they should manage to reassemble the packets, they would still have to crack the 256-bit AES encryption used by Sandia's special secure military communications version.
Text: http://www.eetimes.com/showArticle.jhtml?articleID=165600118