Protocol reverse engineering and interference control of FLASHGET

FLASHGET is a well-known and typical downloading application which belongs to P2P categories. It makes sense to identify and control its protocol accurately. However, it cannot be analyzed by using conventional methods because the process of its downloading is encrypted. For cryptographic protocol, a technique based on protocol reverse engineering was proposed. This method is used by reverse analytic tools to reverse out decryption functions to obtain the structure of protocol and the meaning of encrypted field, and then interferential packages could be constructed, as well as the FLASHGET protocol could be controlled by the bypass interference. The experimental results show that this method can identify and control FLASHGET effectively. In addition, the method also provides a reference to other similar P2P downloading protocols.