http://www.nsa.gov/wwii/papers/start_of_digital_revolution.htm Fascinating article at the NSA site about the heroic efforts to provide long-distance secure voice communications over radio. The good folks at Bell Labs essentially invented digitized, compressed voice, and encrypted it using synchronized pairs of records of random data at each end. Each terminal site had 55 *tons* of equipment! Apparently this astounding - and apparently successful - effort was mostly declassified back in '76, but I first heard about it in Stevenson's Cryptonomicon last year. A remarkable story. Peter Trei