An identifying data set is defined including semi-identifying attributes with semi-identifying attribute values corresponding to an entity. Descriptive records corresponding to the semi-identifying attributes are created. Based on the descriptive records, retention records with retention attributes are created. A composed retention attribute is generated based on applying cryptographic hash algorithms to the retention attributes stored in a database. A retention attribute description is generated with a category and payload corresponding to the composed retention attribute. The semi-identifying attributes with corresponding positions are stored in the retention attribute. Hashes corresponding to the retention attributes are computed based on a composing mechanism that includes logic to compute the hashes. The hashes are combined to generate the composed retention attribute. When a request is received to permanently delete the entity from the database, the entity may be permanently deleted from the database.