ABSTRACT Owing to inefficiency and cost ineffectiveness, the traditional paper-based and human-centralized document management has hardly been applied in modern IT-oriented business environment. Ascribing to the popularity of electronic commerce, the up-to-date document management task has been driven to rely on electronic and systematic approaches. To improve the efficiency and effectiveness of security management for the growing electronic documents, this paper proposes a set of security reasoning models for E-knowledge management applicable over the Internet. Together with the keyword extraction rules, the reasoning models provide the document providers (or the system administrators) with an initial security policy based on the historical data related to user identity, document categories and the abstracts. The security management principles build on the base incorporating the role and content models and working with the centralized knowledge management mechanism to ensure the consistency of enterprise...