Follow Soroush Moradi on Instagram; / soroush.moradi987 With the advancement of communication technology, mobile networks have become one of the main pillars of everyday communication. The SS7 (Signaling System 7) protocol, which was developed in the 1970s, is used as one of the basic protocols for managing communications in mobile networks. Despite the high efficiency of this protocol in managing mobile phone communications, the security weaknesses in it have made it possible to abuse networks and access sensitive information of users. Exploiting these weaknesses, the Islamic Republic of Iran and other repressive governments have used the SS7 protocol to monitor political opponents and hack their information. In this video, technical points of this protocol, real examples of abuse and methods of dealing with it are discussed. SS7 Protocol: How It Works and Security Vulnerabilities SS7 is a set of signaling protocols that allow mobile networks to manage information such as location, connection of calls, text messages and authentication of users. Simply put, this protocol is responsible for managing communications between mobile and fixed networks. However, SS7 has serious security weaknesses. At the time this protocol was developed, it was assumed that all telecommunication companies and networks using SS7 were trusted. For this reason, modern authentication and security mechanisms are not built into this protocol. This issue allows hackers and even governments to gain access to user information and exploit it by accessing the SS7 network. Security Weaknesses of SS7 1. Location tracking of users: The SS7 protocol allows mobile networks to identify the exact location of users in order to provide them with services. By using signal requests, hackers or security agencies can track a person's exact location without their knowledge. 2. Eavesdropping of conversations and text messages: Another weakness of SS7 is the possibility of eavesdropping on conversations and text messages of users. By sending specific requests to the SS7 network, attackers can eavesdrop on a person's conversations and text messages without their knowledge. 3. Bypassing two-step authentication: Many online services use SMS as one of the ways to send two-step authentication codes. By using SS7 weaknesses, hackers can hijack SMS containing these codes and gain access to individual user accounts. 4. Diverting calls and text messages: Hackers or governments can redirect users' calls and text messages to their own servers. This practice allows them to control and monitor the person's communications without their knowledge. The use of SS7 by the Islamic Republic of Iran to hack users The Islamic Republic of Iran has used the SS7 protocol to control and monitor political opponents, human rights activists, and journalists. Some of the methods used by the Islamic Republic include the following: 1. Tracking political opponents and human rights activists: Iran's security institutions have used mobile networks and SS7 to locate opponents and activists and use this information to arrest and detain. they use 2. Eavesdropping on the conversations and messages of the opponents: Iranian security institutions have intercepted the conversations and text messages of the political opponents by infiltrating the mobile networks and using the SS7 protocol and used this information to identify their communication networks. 3. Bypassing two-step authentication: The Islamic Republic has used the weaknesses of SS7 to access the user accounts of opponents and political activists in social networks. By hijacking text messages containing authentication codes, security agencies have been able to gain access to these people's accounts. Available solutions to counter SS7-based attacks 1. Use encrypted messaging apps: Users should use apps like Signal or WhatsApp that encrypt conversations and text messages. These applications can prevent unauthorized access to information. 2. Application-based two-step authentication: Instead of using SMS to receive authentication codes, users should use secure applications such as Google Authenticator that work independently of SS7 and the risk of identity theft is reduced. 3. Shift to newer protocols: Mobile service providers should move towards using newer and more secure protocols such as Diameter, which is designed for LTE and 5G networks and does not have the weaknesses of SS7. 4. Strengthening the security of networks by operators: Mobile operators can prevent SS7 network abuse by applying more authentication and security mechanisms. This includes restricting network access and increasing monitoring of incoming and outgoing signals.