GSM (Global System for Mobile Communication) is a digital cellular communication technology. It is widely applied in many kinds of mobile communication tool, such as mobile phone. The technology uses microwave and signal delivery which are divided by time. For the result, the information signal sent will reach its destination. Nowadays, GSM is known as the largest cellular technology that is widely used by the people around the world. Thus, it used as the global standard for mobile communication.
GSM security mechanism is implemented in three different system components. In order to do wire-tapping, we use information databases and identity of each GSM customer stored in the authentication center in the form of International Mobile Subscriber Identity (IMSI), TMSI (Temporary Mobile Station Identity), LAI (Logical Area Identity) and Ki from those three system components. Therefore, the recommendation from the Government, Badan Intelijen Indonesia (BIN), Polri, and Mobile Vendors are needed to legalize the process.
Along with the development of information and communication technology which open the space line between communication freedoms, there are many tendencies to abuse the technology to commit crime, such as terrorism or criminal. We can not deny that telecommunication media, such as mobile phone, is one of the fastest communications media ever which is not limited by distance and it is also privately in information exchange between individuals.
Due to limitations in obtaining private information, it is difficult for the relevant parties to solve the problems. Not only they could only follow up the problems but they also have a difficulty to prevent those problems. As the students who care about this matter, we have a desire to help to solve the problems by trying to make an application and designing the hardware which have function as a mediator in efforts to find the necessary data and information.
We call the system Intruder in the Darkness (Intrusion in the shadows). It is software that can perform scanning phone number, man-in-the-middle attack and phone tracking. It can be used for searching accurate information of many crimes, such as terrorism that are in the planning and has been going on. Thus, they can be prevented or resolved. Not only the system is worked using a BlackBox but it is also stored inside it. The BlackBox, which is a hardware designed to fulfill the system needed, is connected with a PC.
For twenty-one years, A5 / 1, the same encryption, has been used to protect the privacy of calls under the GSM standard. With the standard that covers 80% of users from around the world, of course, the GSM network is considered as the most secure network. But finally, Karsten Nohl, a Germany researcher, has succeeded to break the GSM security code. According to what has been done by Nohl, it can be assumed that GSM security mechanism is implemented in three different system components that is:
1. Subscriber Identity Mobile (SIM) inside the Mobile Station (MS). SIM contains IMSI, Ki, A8, A3, and PIN.
2. Handset GSM or the MS (mobile phone). Handset contains A5
3. GSM network (such as ProXL, IM3 and Indosat). Encryption algorithms (A3, A5, and A8) are also contained inside the network operator. Network Authentication center contains database of the identity and authentication information of the customers. The information are in the form of IMSI, TMSI, LAI (Logical Area Identity), and Ki of each customer.
From those three system components, we use the database to help us to do wire-tapping.
The algorithm was first developed in 1987 when GSM can only be used in Europe. At the time the algorithm was called A5/1. In order to improve the safety of the algorithm, the development of it has been continued. For the result, in 1989, algorithm A5 / 2 has successfully developed. Both algorithms are highly classified at that time by the parties and the GSM service provider. Iin 1994, the information about these algorithms finally can be known by the public. Then, in 1999, it has been reverse engineered successfully through an ordinary mobile phone by Marc Briceno. Even so, in 2000, when mobile phone service began to grow rapidly and its use expanded, algorithm A5 / 1 eventually be used to secure voice communications. Currently, the development of the algorithm has reached the third generation that is algorithm A5 / 3 which is different from the first ones. Algorithm A5 / 3 is a block algorithm which was adapted from chippers Kasumi algorithm. Kasumi made by Secure Algorithms Groups of Experts (SAGE, part of the ETSI, an European standards department. KASUMI itself is the result of the development of MISTY1algorithms.
Intruder in the Darkness has a function to reduce complicated bureaucracy in searching information of mobile phone users in a faster time (realtime). It also has a function to optimize the utilization of cellular phone (cell phone) as a flexible tool in monitoring people who are suspected or has become a suspect in a crime, especially in criminal and terrorism. For the result, the authorities can prevent and tackle crime, criminality and terrorism occurred.