Stop spoofing: how new filters against harassing calls work

From the August 19th I will enter the First protection mechanisms against spoofingone of the most popular practices in wild telemarketing and telephone fraud. These are technical systems imposed on operators by the AGCOM 106/25/Cons resolution, approved last May, to stem a phenomenon that has made it increasingly difficult distinguish between legitimate phone calls and deceptive calls if not sometimes completely criminal. It starts with the fixed numbers, in November a second step will follow, with a further extension of the blocks also to the falsified mobile numbers.

The spoofingor more precisely Calling Line Identity Spoofingis the falsification of the identity of the calling number. Through VoIP systems or foreign platforms, the most aggressive or incorrect call centers and scammers can make an Italian number appear on the display, often with prefixes attributable to cities such as Rome or Milan, or even to banking institutions, law enforcement officers or entities of which the reliability is recognized. The result is that the user, seeing an apparently reliable number, It tends to respond, sometimes ending the victim of phishing attempts or fraudulent requests. This stratagem, taking advantage of visual trust on the screen, also made the opposition register not very effective, because the real sender remains hidden abroad.

The first filter, active from August 19th, will automatically block all calls from outside Italy that falsely show a national fixed number. In short, goodbye to disguises. I prefix as 02 or 06 can no longer be used as a facade for calls for foreign servers. From November 19th the measure will then be also extended to falsified Italian mobile numberswith a more complex management to distinguish the phone calls of users really in roaming around the world from calls to give birth and rigged by fraudulent systems. Operators will have to carry out cross controls between the real origin of the call and the number displayedblocking or anonymizing those that present discrepancies.

For citizens the system will not require any activation: will be managed entirely at the network level by the operators. This means that apps, recordings or manual actions will not be necessary. The effects should be immediate, with a significant (hopefully) reduction of harassing calls that exploit falsified numbers and a greater security margin for those who respond to the phone, especially in cases of fraud aimed at the theft of banking or personal data.

It remains some critical point to monitor, especially in the November phase, when the filter will have to manage roaming traffic without penalizing, that is, blocking those who call from abroad for legitimate reasons. In some cases, to avoid excessive blocks, operators could opt for the anonymization of the number instead of the total interruption of the call, however leaving the protected user. Despite these complexities, the new system represents the first concrete step towards a sensitive reduction of aggressive telemarketing and scams based on the manipulation of telephone identity.