User manual

A.2 Bluetooth® low energy Security
Figure 16 - Chappe's Optical
Telegraph
"Paris is quiet and the good citizens are content." Upon seizing power
in 1799 Napoleon sent this message on Claude Chappe’s optical
telegraph. Chappe had invented a means of sending messages line-of-
sight . The stations were placed approximately six miles apart and each
station had a signaling device made of paddles on the ends of a
rotating “regulator” arm whose positions represented code numbers.
Each station was also outfitted with two telescopes for viewing the
other stations in the link, and clocks were used to synchronize the
stations. By 1803 a communications network extended from Paris
across the countryside and into Belgium and Italy.
Chappe developed several coding schemes through the next few
years. The station operators only knew the codes, not what characters
they represented. Not only was Chappe’s telegraph system the first
working network with protocols, synchronization of serial
transmissions but it also used data encryption. Although cryptography
has been around for millenniums—dating back to 2000 B.C. — Chappe,
was the first to use it in a wide area network in the modern sense.
Frontline BPA low energy Hardware & Software User Manual 222