US Patent 11803650 Column access control

A database management system receives a request to process a database query on behalf of a security principal. The database management system determines that processing the database query requires access to an encrypted portion of a file containing data subject to access conditions. The database management system determines that the security principle is authorized to use a key that corresponds to the encrypted portion of the file. The database management system then completes processing of the query by using the key to access the encrypted portion of the file.