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:
“The transformation of the impossible into reality is always the mark of a demonic will. The only way to recognize a military genius is by the fact that, during the war, he will mock the rules of warfare and will employ creative improvisation instead of tested methods and he will do so at the right moment.”
—Stefan Zweig (18811942)
“[I]t is a civil Cowardice to be backward in asserting what you ought to expect, as it is a military Fear to be slow in attacking when it is your Duty.”
—Richard Steele (1672–1729)