William Molinié 06:16, December 20, 2022

The discreet intelligence service of the French armies has agreed to open its doors to Europe 1. Throughout the week, we take you to the air base 110 of Senlis-Creil in Oise, to the HQ of the expert centers of the Directorate of Military Intelligence (DRM).

EXCLUSIVE

You have to go underground to access the electromagnetic wave expert center of the Military Intelligence Directorate (DRM).

It's the discomfort of the absence of daylight, but the immense advantage of being able to listen discreetly… On Chief Petty Officer Sarah's computer, a signal has been intercepted somewhere in the world.

The layman will only hear an insignificant succession of high-pitched sounds mingled with purring breath.

"At first glance, we do not understand anything. All the work will be to analyze the signal. Like an onion, we remove the layers to then access the heart of the interception", explains to the microphone Europe 1 the operator-listening, for six years at the DRM.

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Documenting abuses and attributing them

After thorough cleaning, aided by a whole panoply of software, the enigmatic raw sound reveals two voices, this time very human.

This radio discussion could be that of two soldiers on the Ukrainian front.

It will then have to be translated to give it its full meaning.

According to information from Europe 1, it is thanks to this type of interception that certain abuses, whether in Ukraine or in the Sahel, have been documented and then attributed.

Some messages are encrypted and contain valuable information, providing a real-time snapshot of the battlefield.

"The electromagnetic signal allows us to have a fairly precise projection of the forces involved", explains Sergeant Maxime, signal specialist.

"We can thus determine the types of weapon systems used and therefore then attach them to certain nations".

Some messages will never be decrypted

During peaks of activity, as may be the case during Russian bombing campaigns on Ukrainian cities, these soldiers are required to exploit up to several thousand signals each day.

The decryption time can take from a few hours to several weeks or even several months.

Some never will.

A few weeks after their invasion in Ukraine, the Russians realized that the radio links between their troops and their staffs could be compromised.

And so they reverted to the old wire spool technique.

With a limit very quickly reached: the impossibility of covering the immensity of the plains of the East.