Based On The Uclinux The Dhcp Security Set-top Box Research And Implementation,

With the development of Computer technology and network communication technology in Information times and the broad application of Internet, it is clear that 3C (Computer.Communication and Consumer) will converge in the near future which will lead the focus of Computer Industry from the Compute product to Information product. It is the concept of Information Appliance. In the application and development field of Information Appliance, Embedded Operating System will be the most favorite thing in Software Development field. At the same time, in the field of computer science itself, the micromation and specialization is the new direction of the computer world. It also want the support of Embedded System. So, the research of the key technique of Embedded Operating System is a most important thing. But the Information appliances are exposed to work in complex network and might have to face complicated intended or unintended attacks ,so they are unsafe like one computer exposed to Internet ,so we must take measures to ensure the information's safe working.This thesis presents the author's work in research of safe methods of the realization of DHCP protocol in uClinux-based Embedded Operating System in information appliance-- Set Top Box for master degree . Most of the thesis focus on the safe principles and methods of DHCP protocol's realization. Firstly, it describes the development environment of the Information Appliance -Set Top Box (STB) and its relevant technology -secondly ,it describes the reasons to adopt uClinux-based Embedded Operating System in STB: Then it describes three key techniques in detail to ensure the safety of DHCP protocol In uClinux-based Embedded system in STB. The first key technique: using plain-text cipher and MD5 message-digest algorithm to ensure STB and DHCP server's certificate and secure the STB and Server's communications-the second key technique: using HMAC algorithm to realize the safe functions-the third key technique: using IPSEC to realize safe functions o Those three methods' complexity increases in turn and the degree of the security increases as well which depend on the frame of the methods and the complexity of the algorithm .All theose three methods use the unique serial-number or a special slip-window to defend replay attack.