Four Security Operating System Secos Realization

As the coming of the information age , the state secret and personal privacy protection becomes a very important aspect of normal society activity. In order to protect the hosts from intruders on the wide internet, governments and also some organizations from many countries have accelerated the research of information security. Comparing with other developed countries, the domestic study on this area began later, so constructing a secure operation system becomes a key problem to the information security protection. Linux, as a famous open source operation system, with excellent performance and flexible adaptations, makes itself a great develop platform to build a secure operation system.After analyzing the limitation of Linux security, the system architecture of multilevel security is put forward to satisfy the requirement of security, and implemented in SECOS (Secure Operation System). SECOS is a secure operation system with independent intellectual property right, which accords with the requirements of level 4 secure operation system technology defined in GA/T 388-2002. This paper illustrates some key issues of the system, including design method for enhancement of security, improved model from the Bell-La Padula MAC (mandatory access control) implementation , the realization of the model, formal method during the system development, convert channel analysis and its prevention , and secure deletion .As the performance evaluation shows , the design and implementation of SECOS is effective.