Military Use
Spread-spectrum signals are highly resistant to deliberate jamming, unless the adversary has knowledge of the spreading characteristics. Military radios use cryptographic techniques to generate the channel sequence under the control of a secret Transmission Security Key (TRANSEC) that the sender and receiver share in advance.
By itself, frequency hopping provides only limited protection against eavesdropping and jamming. There is a simple algorithm that effectively discovers the sequence of frequencies. To get around this weakness most modern military frequency hopping radios employ separate encryption devices such as the KY-57. U.S. military radios that use frequency hopping include the JTIDS/MIDS family, HAVE QUICK and SINCGARS.
Read more about this topic: Frequency-hopping Spread Spectrum
Famous quotes containing the word military:
“Who are we? And for what are we going to fight? Are we the titled slaves of George the Third? The military conscripts of Napoleon the Great? Or the frozen peasants of the Russian Czar? No—we are the free born sons of America; the citizens of the only republic now existing in the world; and the only people on earth who possess rights, liberties, and property which they dare call their own.”
—Andrew Jackson (1767–1845)
“The military and the clergy cause us much annoyance; the clergy and the military, they empty our wallets and rob our intelligence.”
—Franz Grillparzer (1791–1872)