Personally feel that jammers have a positive guide to people's lives

Using network vulnerabilities to turn your mobile phone into a distracting device and interrupt a small urban network, only a dozen calls are needed. Researchers have found ways to make ordinary phones. In some cases, the jammer can interfere with other calls, such as B. In a movie theater, classroom, or conference room. Phone calls are prohibited in some places. The prison will install jammers to prevent prisoners from claiming to be. This "interference" is not suitable for personal use, and is expensive and has low energy consumption. Because they block emergency calls, they also pose a security risk.

Now, computer scientists have shown that even business phones may change due to software changes. The team led by the Institute of Software Engineering and Theoretical Computer Science exchanged software on mobile phones and took advantage of their weaknesses in the GSM radio standard. Computer scientists presented their findings at a security seminar and will create an electronic device that can suppress cell phone signals.

Run optimized open source software on the replacement phone. Therefore, they deceive the radio antenna mast like a portable jammer and immerse the frequency in a small range of the interference signal. A faulty phone call can prevent text messages and phone calls from being sent to recipients in the area: forging identity and answering questions with strange names. In the worst case, you can even block text messages. Because radio stations send hundreds of square kilometers of status information before being called. This process is called paging. The lead author of the study said: "A call is ready to be sent to all phones in the area." It contains an identification number that each phone can use to check whether it is on the device. "

However, the replacement phone answers these queries and accepts them, calls and text messages faster than other phones. To the transmission tower, it looks as if the real recipient has been notified. But he didn't learn anything. In the best case, only the phone is lost and there is no call. In the worst case, even text messages may be intercepted and read due to cracked encryption and lack of authentication. So far, computer scientists have only tested the GSM standard more than 20 years ago, but have used many modern smartphones when needed. In addition, the researchers wrote, this gap threatens the communication between the machine and the future Internet of Things. Even new UMTS or LTE networks may be vulnerable. Golde said: "Many GSM protocols are duplicates, and paging mechanisms exist in the third and fourth generation mobile standards." A similar attack may be here. "But so far, the correct hardware, especially software, is missing.

The computer used in her research was the same as the previous computer in Berlin, as long as 11 mobile phones could weaken Berlin's network. The scientist explained: "You can respond to all paging requests and block the mobile area." This affects the entire community. However, during peak hours, more calls are needed to satisfy the requests of more disruptive providers. On average, 200 square kilometers in Berlin, an attacker can cover the area.

Mobile jammers are difficult to track down. Researchers say that only by changing the GSM standard can such attacks be prevented. These will be difficult to implement. They complained that the industry refused to include the new standard in the existing network. It will also be expensive, because more authentication and traffic can solve this vulnerability. Since the attacks not only target network operators and organizations, but also individual users, they can cause further financial losses in the event of a security breach.