CLI spoofing is a popular attack method on telecommunication services worldwide. Some international telecommunications providers have introduced security mechanisms in network protocols that can eliminate the vulnerability that exposes them to this risk. So far, many telecom providers, including in Italy, have considered introducing these security mechanisms, but have not yet set precise plans and timeframes for doing so.

CLIC (CLI Certification), a solution designed to enable telecom operators to detect CLI spoofing in time, albeit after the fact, and to take the most appropriate countermeasures, has been developed. The implementation is cost-effective and time-saving and has no impact on the communication protocols. CLIC is an application platform for detecting CLI spoofing that connects phone providers nationwide via a blockchain network and allows participating providers to record call details and certify them to other members. This is to enable each of them to detect the integrity of CLI in a timely manner by comparing calls coming into their network with genuine calls authenticated by the originating operators. The effectiveness of the solution is higher the more operators participate in the system.