Length Identification of Unknown Data Frame

Unknown protocol identification is widely used in the field of network and information security. Most previous researches focus on known protocol identification and analysis of network layer and above. However, the research on unknown protocol is an essential part for ensuring the safety of information system. In this work, a length identification method of unknown data frame is proposed based on characteristic searching of bit stream of unknown protocol, which can analyzes and researches protocols unknown from physical layer to application layer and determines the length of frame effectively. This method can adapt to the identification of unknown communication protocol and is significant to network and information security.