Configuring Clark-Wilson Integrity Model to Enforce Flexible Protection

Clark-Wilson model is widely used to protect commercial information against unauthorized modification. However, due to only single-level data protection support and no attention paid on difference of importance level of protected data, the model does not apply to many scenarios. An enhanced Clark-Wilson model is put forward in this paper to provide flexible protection. By using traditional integrity level as basis for modification to objects and regarding procedures as special data items, integrity protection for upgradeable software is provided. The size of access control triple set is reduced greatly by adoption of user-domain-type format. The model is enforced for software protection of a PC-based metrological instrument. Through proper configuration, anti-tampering protection for upgradeable software is achieved with CW-triples reduced to less than 10.