Trusted Software Constitution Model Based On Trust Shell

Because the guaranty of trustiness wasn't considered enough in traditional software development methods, the software developed in that methods lack effective measures for ensuring its trustiness. However, trusted computer based on TPM can be of temporary trustiness in the initial phase, once software failures and malfunctions occur, especially when software is attacked maliciously, it will bring tremendous loss. The trustiness as a special representation of software quality has drawn more and more people's attentions, trusted software can ensure that the software is always works in the intended way and goes towards the intended direction and will not result in malfunction or failure largely even if caused by malicious attacks, or system errors. How to ensure the trustiness of software will be an inexorable trend of software development and application. Therefore, it is of great theory significance and practical value to conduct research on the constitution of trusted software.Combining agent technique with the support of trusted computing provided by TPM, a trusted software constitution model based on Trust Shell (TSCMTS) is demonstrated in this paper, Trust Shell ensures the trustiness of software logically. The concept of Trust Engine is proposed, which extends the"chain of trust"of TCG into application, and cooperates with TPM to perform integrity measurement for software entity to ensure the static trustiness; Data Structure called as Trust View is defined to represent the characteristic of software behavior. On the basis of that, through verifying whether the dynamic behavior of software satisfies the trustiness constraints at runtime, Trust Engine guarantees the dynamic trustiness of software behavior. For the purpose of improving the accuracy of trustiness constraints, a strategy of determining the weights of characteristic attributes based on information entropy is proposed. Simulation experiments illustrate that the trustiness of software developed by the TSCMTS is improved effectively without performance degradation.