Encryption is a method of scrambling the voice signal so
that only radios with the encryption code can hear each other. This prevents
other people from listening in on your conversations.
Radios that offer encryption are more expensive, so this
only important if you are transmitting sensitive information.
There are several levels of encryption, basic voice inversion all the way to
federal level AES/DES. D.E.S. stands for Data Encryption Standard,
A.E.S. is Advanced Encryption Standard
A standard DES encryption key is 56 bits long. Although considered very secure
at the time of it's release in the mid 1970's, advancement in technology has developed
techniques to crack DES keys in meaningful time periods. In 1999 a distributed
computing project managed to crack a DES key in 22 hours and 15 minutes,
therefore DES encryption is no longer considered strong enough for high
AES encryption keys can be 128, 192 or 256 bits
long. Most commonly the 128 bit key length is used - giving a total of 3.4 x
10^38 possible keys.