Security Policy
• Commercial
May have sensitivity requirements
May have needed to know requirements
Access allowance does not confer a degree of trust
Normally no central authority to control either clearances or classifications → less formal access rules
Commercial Security Policies: Well Formed Transactions
Defines who can do what to various types of data, and in what order
• Steps must be performed in a certain order
• Exactly the steps listed must be performed
• Individuals who perform the steps must be authenticated
• Introduces concept of constrained data items which are processed by transformation procedures
Transformation procedure performs only particular operations on specific kinds of data items
Maintains integrity of data items