Encryption

Is there a scanner that will listen to TG’s that are encrypted? I noticed tonight my SDS100.. I was held on my local sheriff TG but only hearing one side of a conversation. I could hear the dispatcher, and not always really. But I never heard the officer talking. Then I saw where it usually says P25 it was saying ENCRY.. usually I listen to this very TG with no problem. Is it possible that only the radio the officer had was transmitting in encryption? I assumed if I normally hear all the traffic then the TG wasn’t encrypted, but maybe I’m misunderstanding how actual encryption works. Thanks for any input

tommul05 said:

Is there a scanner that will listen to TG’s that are encrypted?

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No. The whole point of encryption is to make it mathematically impossible to listen to the conversation without the key (which you aren't going to get.

tommul05 said:

Is there a scanner that will listen to TG’s that are encrypted? I noticed tonight my SDS100.. I was held on my local sheriff TG but only hearing one side of a conversation. I could hear the dispatcher, and not always really. But I never heard the officer talking. Then I saw where it usually says P25 it was saying ENCRY.. usually I listen to this very TG with no problem. Is it possible that only the radio the officer had was transmitting in encryption? I assumed if I normally hear all the traffic then the TG wasn’t encrypted, but maybe I’m misunderstanding how actual encryption works. Thanks for any input

Click to expand...

The way encryption works is that encryption mode selection by the field unit can be programmed as slaved to a specific talkgroup or can be user selectable by a switch. The same options exist with the console. Regardless of how the system is set up, the receiving party will always hear the encrypted audio if the transmitting party has switched it on. The same goes for hearing clear audio when one party has selected an encrypted mode and the other has not and is transmitting.

In the case that you describe, the officer had activated encryption by either a toggle switch on the radio, or had selected a talk group on the rotary knob that has encryption slaved. The dispatcher either forgot to engage their encryption (because it sounds same as clear in P25) or did not feel it necessary for a short exchange to do so. Likely the officer had some confidential information to convey and switched the encryption on for that moment.

Operating in this way can cause confusion and potential to leak confidential information, if the dispatcher were to repeat the info. Normally the radios should be programmed to slave the encryption mode on when selecting a specific, dedicated encrypted TG. The dispatcher would have that same encrypted TG on the console screen for selected or unselected audio path, and would use either the main PTT button or Instant Transmit button as required to reply.

Clearly there may be training issues going on.

Be happy the department has not engaged full time encryption.

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There are no commercially made scanners that will decrypt encryption. The ECPA makes it a federal crime to decrypt encrypted communications of others.

There is open source software designed radio (SDR) code that will perform decryption, however one must have physical access to the 56 bit DES or 256 bit AES key.

The key is usually known by only one person, or simply blindly entered into a key variable loader where it cannot be retrieved.

56 bit DES has already been cracked by researchers within a few days computer time. It is theoretically possible to decrypt encryption given fast enough computers and knowledge of clear text components of the audio stream such as silence and synch bits. I am sure folks are attacking this problem, however, for obvious reasons, no one will be bragging about it.


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"listen" to encryption - you probably mean "decrypt so I can listen" but you might also mean "hear/see the garbled/encrypted transmission even if encrypted" (maybe not).

As has been stated, encryption (full or partial) is there to keep you from listening and there is almost nothing you can do to overcome that.

As for scanners - Uniden tends to suppress encrypted transmissions such that you never even know they are there.... there are pros and cons to this depending upon your interests.

Whistler scanners will actually stop on the encrypted activity - it will still be encrypted but at least you know it's there.

Yes it is possible that a mobile is replying encrypted to a non encrypted dispatch. Or maybe the user has selected clear by mistake.

Listening to the garbled transmissions can be annoying for most this is why Uniden suppresses (mutes) any encrypted traffic.

I do a lot of TG hunting and being able to temporarily disable the Auto-muting would be very useful. That way I can confirm the TG is indeed active and ENC

If you're logging with ProScan or using trunked discovery, encrypted activity is logged, even though the garble noise is not heard. The scanner logs the hit, and then immediately resumes scanning if encryption is detected.

Some agencies will use partial encryption. The dispatcher will be in the clear, while the mobile and portable radios will be encrypted.
Several agencies, both law enforcement and FD/EMS, operate in this manner in La Paz County, AZ, as a standard practice.

I don't know if that is what the agency that you are trying to listen to has done.

John
Peoria, AZ

tommul05 said:

Is there a scanner that will listen to TG’s that are encrypted?

Click to expand...

What would be the purpose of running encryption if any consumer could go out and purchase a scanner that would decrypt it?

RFI-EMI-GUY said:

There is open source software designed radio (SDR) code that will perform decryption, however one must have physical access to the 56 bit DES or 256 bit AES key.

Click to expand...

What software is that?

Homeboys-Scanna said:

What software is that?

Click to expand...

https://youtu.be/wShOLgW2tmI

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My hometown pd went to full time encryption. I got so fed up with hearing "You'll figure it out, you're a radio genius. Or "the Asian kid with the computer, will crack it". Then, they wanted to know, what can you do to your scanner to hear it. I stopped responding.

pdfdems286 said:

My hometown pd went to full time encryption. I got so fed up with hearing "You'll figure it out, you're a radio genius. Or "the Asian kid with the computer, will crack it". Then, they wanted to know, what can you do to your scanner to hear it. I stopped responding.

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When encryption comes to my town I will be putting my efforts into building a public safety radio detector so I can detect nearby public safety activity.

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RFI-EMI-GUY said:

When encryption comes to my town I will be putting my efforts into building a public safety radio detector so I can detect nearby public safety activity.

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Click to expand...

Well in theory that should be easy enough by programming the inputs to the repeater frequencies. Your radio will act almost like the Beartracker Warning System.


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Mike445 said:

Well in theory that should be easy enough by programming the inputs to the repeater frequencies. Your radio will act almost like the Beartracker Warning System.


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Actually, in addition to that, two other concepts:

1) An 806 MHz preselector tuned to public safety spectrum followed by a preamplifier, diode detector and log amplifier and an audible indicator. No tuning required.

2) A scanner tuned to the LO frequencies emanating from common P25 radios. No transmission required, mere proximity to receiver will pick up.


Imagine thousands of hobbyists with such receivers tied into the internet and overlaying hits on a Google map!

RFI-EMI-GUY said:

Imagine thousands of hobbyists with such receivers tied into the internet and overlaying hits on a Google map!

Click to expand...

https://www.rtl-sdr.com/localizing-transmitters-to-within-a-few-meters-with-tdoa-and-rtl-sdr-dongles

https://www.rtl-sdr.com/kiwisdr-tdoa-direction-finding-now-freely-available-for-public-use

nd5y said:

https://www.rtl-sdr.com/localizing-transmitters-to-within-a-few-meters-with-tdoa-and-rtl-sdr-dongles

https://www.rtl-sdr.com/kiwisdr-tdoa-direction-finding-now-freely-available-for-public-use

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Excellent. I wonder if the KIWISDR can be used with a UHF down converter. Will a GPS derived LO be necessary for preserving the TDOA? Hmm, I like this...

RFI-EMI-GUY said:

Imagine thousands of hobbyists with such receivers tied into the internet and overlaying hits on a Google map!

Click to expand...

We already do that since ages ago to be able to track aircrafts that doesn't give their positions, like mil aircraft and smaller aircrafts and some helicopters. It's called MLAT and I use a $50 RaspberryPi with a $50 SDR dongle.

Multilateration (MLAT)
https://www.flightradar24.com/blog/how-we-track-flights-with-mlat/

/Ubbe

RFI-EMI-GUY said:

1) An 806 MHz preselector tuned to public safety spectrum followed by a preamplifier, diode detector and log amplifier and an audible indicator. No tuning required.

Click to expand...

Will that frequency spectrum be isolated to be used by only public safety or will there by other users?
Isn't a responder keying his radio when he acknowledge to accept the incident, maybe miles away and then only key it again when he arrives at the scene, too late to get any kind of pre-warning?

Even expensive filters that have 80dB attenuation outside of its passband would pass a signal if a transmitter would be close enough, like a 100 meters.

2) A scanner tuned to the LO frequencies emanating from common P25 radios. No transmission required, mere proximity to receiver will pick up.

Click to expand...

Modern radios doesn't emit much stray RF. You could probably hear a local oscillator at 2 meters distance at best.

/Ubbe

What if the same system also carries a ton of non-LEO comms?

Locally - easily a 1/2 or so would be busses,ambulance transport, DOT. etc.

RFI-EMI-GUY said:

Actually, in addition to that, two other concepts:

1) An 806 MHz preselector tuned to public safety spectrum followed by a preamplifier, diode detector and log amplifier and an audible indicator. No tuning required.

2) A scanner tuned to the LO frequencies emanating from common P25 radios. No transmission required, mere proximity to receiver will pick up.


Imagine thousands of hobbyists with such receivers tied into the internet and overlaying hits on a Google map!

Click to expand...