Police Software?

[Renegade631]

Right on about the ASCII text messaging being free to monitor. Anything not encrypted is fair game as far as the laws governing public airwaves are concerned. It's the CAD dispatch systems and the NCIC data that are encrypted in order to protect info that may case subjective. There may be portions of the CAD traffic that may also be ASCII text, but whether or not those are encrypted will be system dependent. The pre-selected response codes on both ends that are selected by the operators pressing a designated button on the keyboard won't be decipherable because they'll be software defined responses. Pretty much anything that falls into the standard fields on the CAD screen (call code, location, names, records, etc) will be software encrypted, which you will need the current software and encryption coding to decipher, but the additional info/comment fields and some others that are optional may well be ASCII and unencrypted.

How would one go about reading the unencrypted data then?

 

[CCHLLM]

Any ASCII messaging software that can take an audio input through a soundcard will get you the unencrypted ASCII data stream. The problem will come when you try to decipher what most of the character streams mean. Just because it's not modulation encrypted doesn't mean there's not a character shift scheme or ASCII compressed data scheme in place to keep the formal fields in the CAD sequences somewhat secure and to keep transmission times lower. In addition, the pre-programmed status buttons are programmed with nothing more than a code sequence or an FSK response that is always the same. Without knowing what each sequence means would be like being without a 10-code/Signal code/Color code sheet for the local area you're listening to. "Enroute" may be character code "F34A", and "Arrived" may be "F34B", and "In service" could be "C123" and "Out of service" could be "C124", but unless you know or figure out what that particular "shorthand" sequence means each time you see it in the ASCII stream, it'll mean nothing.

With all that being said, there's nothing to say that manually typed unsecured messaging texts won't be completely in the clear. That's system dependent.