The instance-based multilevel security model

Managing data securely is a critical issue in modern organizations Multilevel database systems offer one approach to security that assigns various security levels or clearances to the data in a database and to users of a database The objective of multilevel databases is to share data that have been assigned different security levels, while preventing unauthorized access to data by a user with a given clearance level to data at a higher security classification Current models store information in different security levels separately to prevent unauthorized access to data by users at different levels However, leakages could still occur in cases such as those involving null values and those where sensitive data is included in the key field(s) of a relation In this research, we design a novel security model, the instance-based multilevel security model, to solve problems associated with existing security models We define the model, propose data access and integrity rules, and develop a two-layered access control method Finally, we prove that the model is secure and identify areas for future research.