### Why do we need multi-level security for relational databases? DoD and similar organizations will have classified, labeled and structured data that they would like to store in databases. ### How can we apply [[Bell and LaPadula model|BLP]] to such databases? - Read at the same level or from dominated accesses classes - Write at the same level as [[SELinux]] - Trusted users allowed to violate this trust ## Access Class Labels or access class In structured data, attribute values or element values, a row of those makes a tuple. Typically this is a user’s information. A collection of these tuples, arranged in a table gives us a relation. ### Granularities What do we associate an access class with? Possible granularities - Database - Table - Tuple - Element/Attribute > The granularity should be at the element/attribute level.