Systems, methods, and other embodiments associated with maintaining referential integrity while masking database columns are described. One example method includes determining a transitive closure for dependency relationships involving a column to be masked and other columns related to the column to be masked through a dependency relationship. The example method may also include identifying a root column for a column in the transitive closure and creating a mapping table that stores original values and masking values for the root column. The method includes masking the root column and related child columns based on the mapping table in a manner that maintains referential integrity between the root column and the child column. Integrity may be maintained by masking corresponding values in the root column and a child column(s) with identical mask values from the mapping table.