E F Johnson Company 2425333 사용자 설명서

5300 ES Series Mobile Radio Operating Manual

Section10

This radio may be equipped to provide secure communication on some or all channels. 
This feature encrypts the voice so that it can be understood only by someone using a radio 
equipped with a similar encryption device and encryption codes.

If equipped with the Clear/Secure option switch and the current channel is programmed to 
allow switch selection, secure communication can be manually enabled and disabled by 
that switch. Otherwise, channels are strapped to Clear or Secure operation (see Section 
10.3). Secure communication can be programmed on a per channel or per talk group basis 
to operate in various ways. When a secure call is received, the LED flashes Red and 

 is 

indicated in the display. 

SecureNet encryption digitizes the voice and then encrypts it using the DES algorithm. It 
uses a 64-bit encryption key. The SecureNet protocols include the following algorithms:

• DES (Data Encryption Standard) provides a level of security, and also uses cipher 

feedback. It was originally designed to be used only by the Federal government.

• DES-OFB - A form of DES encryption for digital channels that uses output feedback. 

This protocol does not result in the degraded range that occurs with analog channels.