Encrypted Audio

Status
Not open for further replies.

brscanning

Member
Joined
Dec 18, 2002
Messages
580
Location
Baton Rouge, LA
Could anyone tell me if the attached audio sample is an encrypted signal or simply my scanner's failure to properly decode the signal? I was under the impression that encrypted signals sounded like static. The sample is from Louisiana's 700 MHz P25 system. I can sometimes hear one side of the conversation while the other side sounds like the sample audio.

Another question is whether the encryption is controlled from each radio? For example, can one side of the conversation be encrypted while the other is not?
 

Attachments

scannerfreak

Moderator
Database Admin
Joined
Jul 3, 2003
Messages
5,185
Location
Indiana
That is digital encryption. If enabled, the user can manually switch between clear and encrypted modes. So, in your case if hearing only one side in the clear, one side has the switch flipped and the other does not.
 
Last edited:

WayneH

Forums Veteran
Super Moderator
Joined
Dec 16, 2000
Messages
7,464
Location
Sitting in an airport somewhere
All a radio needs is the key loaded and it automatically decrypts regardless of the radio's settings.

There are more complicated examples with multiple keys but that's the gist.
 

brscanning

Member
Joined
Dec 18, 2002
Messages
580
Location
Baton Rouge, LA
Thanks for the replies. I suspected it was encryption since it was consistent. My doubts came from a couple of statements I found on the web that encryption sounded like hiss or static. I have even heard a sample of an encrypted signal that did indeed sound like static.
 

WayneH

Forums Veteran
Super Moderator
Joined
Dec 16, 2000
Messages
7,464
Location
Sitting in an airport somewhere
Thanks for the replies. I suspected it was encryption since it was consistent. My doubts came from a couple of statements I found on the web that encryption sounded like hiss or static. I have even heard a sample of an encrypted signal that did indeed sound like static.
That's the older 12kbit analog encryption commonly referred to as SecureNet. It's a rush of static/squelch with a beep at the end.
 

fourthhorseman

Member
Premium Subscriber
Joined
Feb 3, 2009
Messages
2,072
Location
So Far Away....
curious,,
i hear that sound alot here in philadelphia-apco-p25,
the same exact audio in fact...

i hear dispatch radio back with replies that the transmission
is unreadable..
i always thought it was poor signal/poor decode of the digi stream...

the officer usually cuts back in and is choppy-mostly clear after dispatch
advises that its a poor signal..

very informative..
 
Status
Not open for further replies.
Top