Decrypt P25 Radios

This course is taught by Andrew McTaggart, a Customer Support Engineering Specialist at Tait Communications. Prior to that, he was a product trainer on P25 digital radio communications equipment.

In this topic, we’ll introduce the P25 standard. P25, or Project 25, is a suite of standards developed to provide digital voice and data communication systems suited to public safety and first responders.

Project 25 was initiated by the, or APCO. APCO International is the world’s oldest and largest organization of public safety communications professionals. Since 1935, APCO International have run a series of projects aimed at solving unique problems telecommunications professionals encounter. Project 25 concerns the development of a standard for digital radio equipment embracing the public safety-focused features of interoperability, spectrum efficiency, and cost economies. An important feature of P25 is that the development is user-driven. The needs of public safety professionals are paramount. Project 25 is not finished. The standards are constantly being enhanced and refined as new requirements are identified.

Another key aspect of P25 is the importance of migration strategies and backwards compatibility with existing equipment. Digital P25 radios even include an analog mode of operation that is compatible with existing FM radio equipment. The, or TIA, formulates and maintains the TIA-102 series of standards for APCO P25, on behalf of APCO International. The Project 25 standards enable interoperability among multiple manufacturers of P25 products. This results in a greater range of products, both mobile and portable radios used by front line staff and also the network equipment, stored on hilltops and in dispatch centers. Multiple manufacturers allow for price competition, both during the initial tender for a new radio system and throughout the life of the system as it’s expanded and maintained. It also allows for different agencies to communicate together, even if they’ve purchased their P25 equipment from different vendors.

If you’ve lost interest in that DVB dongle you bought to give software defined radio a try you should bust it back out. [Harrison Sand] just finished a guide on. The project, which results in the crystal clear audio reception heard after the break, uses a whole lists of packages on a Windows box to access the emergency bands. Ce 0197 x driver download.

SDRSharp, which, handles the hardware work. In this case the dongle is a Newsky TV28T v2 module that he picked up for a few bucks. He’s also using some support programs including the Digital Speech Decoder which turns the data into audio.

Enabling P25 encryption is easy. A channel or group is programmed to use encryption and a key is loaded into each radio that uses that group. DES uses a 56-bit encryption key and AES uses a 256-bit encryption key. The type of encryption to use depends on the type of information you’re protecting.

We wonder how many areas this will work for. It was our understanding that law enforcement was moving to encrypted communications systems. But all we really know about it is that. Posted in Tagged,,,, Post navigation. It’s not that they can’t agree on a standard.

It’s that departments are funded separately. The state police might want to upgrade their system and tell everybody to use “Encrypted Gizmo 2013” but that means now the County Sheriff dept. And the local Police have to buy all new equipment for their handhelds and vehicles. The local PD might barely have enough money to operate and can’t afford new radios. That’s not to mention the federal agencies involved either.

I’m 99% they’d all be using the same standard if every time the protocol switched the federal government would buy the radios for everybody. Actually my example is Australia. Also TETRA is really the defacto standard for modern 2-way communication, it’s just a question of who will pay for the infrastructure. In Great Britain the Airwave project was created in a public-private partnership which has the overseeing entity Airwave Solutions making money hand over fist every time anyone in the country hits the PTT button. In Australia the states have taken a dim view of going to the extent to encrypt communications and then route it through infrastructure owned by a private company, so instead they setup their own. There’s no doubt the entire state will move to the same system eventually (in this case P25) however the move will take time.