Online training in English – Study of the security of PMR systems – How do Motorola MotoTRBO enhanced privacy RC4 40 bits works?

In digital PMR networks using the DMR standard, several types of privacy (ciphers/encryptions) are used, they are divided into 2 types:

  • Low level encryption, also called « basic privacy ». These are the first-level encryption and uses simple mathematical algorithms
  • Enhanced privacy using more robust algorithms such as ARC4, DES or AES.

All encryption types are not equal, some can easily be hijacked and others much less, in fact it will mainly depend on the time and means deployed by hackers to achieve their ends.

Today, Motorola as well as several members of the DMRA (such as Hytera) have succeeded in agreeing and adopting a common cipher compatible between the different members of the DMRA.

This cipher, initially designed by Motorola, has several names:

  • Motorola Enhanced Privacy RC4/ARC4
  • Motorola EP
  • Motorola EP-RC4
  • Motorola EP-ARC4
  • RC4/ARC4 enhanced encryption
  • DMRA Enhanced Privacy RC4/ARC4

All of these names actually represent the same algorithm named differently.

This encryption method is now commonly used in DMR networks, but a question arises: is this encryption secure? Is my PMR network sufficiently protected if I use it? Can a hacker hijack it and listen to my network?

These are the 3 questions I answer in the ARC4 40-bit Advanced Encryption training.

Click here to access to the online training in English

What does this online training contain?

This training contains both the part concerning basic privacy (see the description here) [15 chapters – 49 videos – 4 hours of training] as well as the part concerning advanced Motorola / DMRA ARC4 40-bit encryption [6 chapters – 14 videos – 2h of training].

All videos are in English.

These 2 training courses contain theoretical lessons and practical exercises.

Chapters are organized into blocks of multiple videos lasting 3-20 minutes each so you can easily stop and pick up where you left off.

The main ciphers covered (in the training on advanced ciphers):

  • What is the difference between basic privacy and enhanced privacy ?
  • How does Motorola Enhanced Privacy RC4 / ARC4 encryption work?
  • What level of security does it offer? Can it be hijacked? If yes, how ?
  • How to use DSD to extract useful information?

Click here to access to the online training in English

What does contains the 6 chapters of this online training ?

  1. The basics principles of encryption – Basic vs enhanced privacy, what’s the difference?
  2. The content of the PI Header in DMR
  3. The Motorola / DMRA Enhanced Privacy ARC4 encryption, how does it work?
  4. Practical workshop – ARC4 decoding
  5. The concept of « Late Entry »
  6. Does ARC4 40-bit encryption protect you well and can it be hijacked?

Click here to access to the online training in English

What is the cost of this training?

2,400 EUR (VAT included) / 2,000 EUR (VAT excluded)

Click here to access to the online training in English

How is the registration process?

Click here, complete the form and pay for your purchase by Care Bancaire or by PayPal

The payment process is managed and secured by Stripe or PayPal (your choice).

Once the payment has been validated, you will immediately receive a confirmation email as well as your identifiers to create a password and connect to the online platform (

If you are a company, your invoice will be automatically sent to you by email at the same time as your login details (for individuals who would like to receive their invoice, contact me).

Click here to access to the online training in English

What are the technical prerequisites to be sure to fully understand the training?

Mandatory technical prerequisites:

  • Know how to use DSD [Digital Speech Decoder] (we are talking about the open source version of DSD available here, NOT DSDPlus)
  • Know how to edit and run a batch file (.BAT files on Windows or .SH files on Linux)

Recommended technical prerequisites:

  • Know how to operate an SDR receiver
  • Have technical knowledge of radio transmissions
  • Know how to read English
  • Understanding Boolean logic (AND, OR, EXCLUSIVE OR logic gates)
  • Have a knowledge base in DMR, dPMR, NXDN
  • Understand numbers in hexadecimal format

Optional and totally optional technical prerequisites:

  • Have radio equipment on hand (to reproduce the exercises)
  • Have knowledge of cryptography
  • Possibly know how to code in C/C++ (if you want to modify the DSD code)

Click here to access to the online training in English

I made a mistake, can I get a refund?

No, once the payment has been validated you will have immediate access to all the training, therefore it will be impossible for you to get a refunded (section 6 of the terms and conditions).

Before paying on the selling page you’ve normally checked a small box :

« I noticed that my purchase can NOT be refunded.
By checking this box, in accordance with the provisions of article L.221-28 of the Consumer Code and the General Conditions of Sale of the company 1GénieSup, I accept that the execution of the contract may begin upon confirmation of the order. and I thus waive my right of withdrawal (section 6 of the terms and conditions) »

Is this online training in French or in English?

The training exists in 2 languages, French and English but you must choose the one you want, on this page it is in English.

If you want to buy the training in French, go on to this page.

I made a mistake, I bought the English version when I wanted the French version, what should I do?

Do not panic, contact me I will make the switch.

I bought the training but I lost my identifiers and/or I no longer know how to connect to it, what should I do?

It’s very simple, go to , then log in with your identifiers, if you have forgotten your password, click on « Forgot your password« .

Alternative method: You can also find your training and connect using this page:

Convinced and want to buy this online training?

Click on the link below here and let yourself!

Click here to access to the online training in English