How does the authentication system that comes into effect in October work?

A first step in the building. Starting October 1, a new tool aimed at improving consumer protection against the scourge of telephone scams will come into force. A weapon that the authorities are counting on to prevent scammers from spoofing numbers, particularly in the context of the fake bank advisor scam, as Julien Lassalle, head of the cashless payment method monitoring department at the Banque de France, recently recalled in our columns.

Concretely, from next month, telephone operators will have to guarantee “the authenticity of the numbers” displaying an identifier on the phone screen of the person called or receiving a message. And this, in application of the Naegelen law aimed at regulating telephone canvassing and combating fraudulent calls, adopted on July 24, 2020. The objective? That fraudsters can no longer attribute to themselves the numbers of banking establishments or public organizations such as Social Security.

The law now requires operators to be the guarantors of the authenticity of numbers and, if not, to be able to:“interrupt the routing” of the call or message from one phone to another. On the line owner’s side, there will therefore be no significant change, since fraudulent calls should normally have been “confused” even before any bell rings. Furthermore, the text voted on provides that “operators ensure the interoperability of the authentication devices implemented”. To this end, the implementation of the caller ID authentication device may “rely on technical specifications developed jointly by the operators”.

Also readFake bank advisor scams cost the French nearly 375 million euros in 2023

A system that is currently limited

A particularly complex means of control to set up, according to the French Federation of Telecoms (FFT), which had expressed a certain number of doubts about the feasibility and effectiveness of this authentication certificate. And this, to the extent that there are more than 200 operators in France, among which the best known, Bouygues, SFR or Free, but also La Poste Mobile and other players present on the business market. “It took a long time and was very complicated to implement, and required a lot of investment, both technical and human, from the operators.”confirms Romain Bonenfant. The director of the FFT explains that the French operators he represents were forced to work hand in hand, to communicate with each other and to imagine a common system to develop this unique solution that does not exist anywhere else.

With one issue at stake, that of sharing all telephone numbers existing in France, and their owner. “That was clearly the number one technical problem: how do we create a common system?”recalls the engineer. To do this, on the model of what already exists in the case of a request for portability of a telephone number, everyone agreed to play the game.

However, the engineer is already pointing out the system’s limits. According to him, the authentication device “does not work on all technologies” and will therefore not be able to apply – initially – to the copper network, nor to the mobile network, nor even to corporate telephone networks. “On October 1, we will begin testing cuts on unauthenticated landline-to-landline calls excluding copper lines.”. A “first phase” which consists of setting up the foundations of the system, before its scope of action is gradually extended, in particular to the mobile network, recognizes Romain Bonenfant.

So don’t worry if the unwanted telephone canvassing continues for a while: “the work continues”assure the operators, sometimes disconcerted by the inventiveness of the fraudsters, and the speed at which they manage to find new ways to get around the blocks put in place. Sometimes in vain. And if there is not yet a perfect firewall system, the French Federation of Telecoms (FFT) calls on everyone to be extremely vigilant and insists on the need to educate telephone subscribers. And to hammer home: “It is important to understand that a bank advisor, for example, will never ask for a credit card code or other information over the phone.”