Abstract: Avionics systems require aviation tasks to be definite, predictable and controllable. This article makes a thorough analysis of the requirements of an avionics system software in terms of security, dependability, integrity and real time. The definition of the trust software in integrated avionics systems is proposed. The trusted computing technology is introduced for the first time into an integrated avionics system, and the architecture of the trust software is established. Based on these, the execution environment of the trust software is established and the technology of its dependability improvement is presented. These developments will guarantee that the integrated avionics system tasks are predictable, which is of vital importance for task execution and security. These technologies lay the foundation for the development of trust softwares in integrated avionics systems which will be applicable to research on large airplanes in China.

Key words: integrated avionics system, trust software, mini trusted computing base, dependability improvement, security systems