Patent ID: 7461268

Claim:
A method of handling secure data in a secure system, wherein the secure data is passed between a processor and memory external to the processor, comprising: maintaining a security version parameter and master key data in persistent storage on the processor; storing first and second copies of an encrypted data structure in external memory, wherein at least one of: the encrypted data structure or an integrity check value calculated therefor are affected by the security version parameter; dynamically updating the security version parameter without modifying the contents of the persistent storage; overwriting the first copy of the encrypted data structure with a new encrypted data structure, wherein at least one of: the encrypted data structure or an integrity check value calculated therefor are affected by the updated security version parameter; reading back the first copy of the new encrypted data structure; determining if the first copy of the new encrypted data structure read back is valid; and modifying the persistent storage to reflect the updated security version parameter only if the first copy of the new encrypted data structure is valid.