An LUN/LBA interface is utilized to obtain the benefits of a content addressed storage (CAS) interface. Reference data is manipulated in a manner similar to a CAS system, where an object ID (OID) table is used to maintain OIDs generated for hashed LBAs. A first tier logic block is used to provide a LUN/LBA storage interface to application programs and to facilitate the writing of reference data. A second tier logic block hashes the content of reference data to be written and stores the OID generated to the first OID table. A third tier logic block facilitates writing the reference data to an LUN and to verify the accuracy of reference data to be read from the LUN. Reference data may be written to a storage area in accordance with a write-once, write-many, or write-many with versioning policy.