Patent ID: 7467284

Claim:
A method of enabling external data storage in a system including a primary processing device, having a processor and a primary data storage unit, adapted to process active records in the processor and configured to store data belonging to active records in the primary data storage unit; and a secondary data storage system, accessible to the primary processing device, wherein the method includes: storing data belonging to an active record in the primary data storage unit; externalising the record by transferring at least a piece of data belonging to the record to the secondary data storage system for storage, wherein the externalising of the record includes the receiving of at least one call initiated by an application program using data belonging to the record to an application programming interface arranged to send the piece of data to the secondary data-storage-system; dividing the piece of data into a plurality of parts, receiving a plurality of externalisation messages, each identifying a data section including data corresponding to an associated one of the plurality of parts and transferring at least the identified data section in response to each externalisation message; and calculating an authentication value for each part of the piece of data and including data reflecting the authentication value in the data section that includes data associated with that part, wherein the authentication value for at least one part is calculated using information derived from a further part as input.