Bonjour ¨¤ tous
A few Historical notes, please....
Spread Spectrum
The first frequency hopping spread Spectrum invented in 1890s by Nikola Tesla for a remotely controllable boat.
In 1942 famous actress Hedy Lamarr patented another form of FHSS for Secret control of torpedoes.
First practical use of spread Spectrum was in top secret 1942 SIGSALY speech encryption machine.
See NSA/NCM sites and my IEEE SPECTRUM article for SIGSALY Quantizer reconstruction.
PRN, and true random Ciphers and coding....
Vernam at AT&T patented a TTY Baudot true random key encoding in 1920s.
Early PRN was used in 1936 Siemens T-52 cipher teletype rotor machine "Gehiemeschriber"
Claude Shannon at BTL, prooved unbreakable cipher theory in a top secret 1942 paper, later published in 1949, using a true random key
Hope this background interesting to some of you!
Bon journ¨¦e
Jon
Froggie the Gremlin