Patent ID: 7428642

Claim:
A storage system comprising: a plurality of logical devices; and a disk controller having access to said plurality of logical devices, said disk controller controlling a transfer of data stored in one device selected from the plurality of logical devices to another device selected from the plurality of logical devices or an additional device to which the disk controller is coupled; and a conversion definition table to be examined by said disk controller prior to the transfer of the data, the conversion definition table containing rules regarding the transfer of the data between said one device and said another device, including whether the transfer is possible, and if so, whether the transfer is unidirectional from said one device and said another device or bi-directional between said one device and said another device, wherein when said another device has access permission for the data stored on said one device, the conversion definition table defines whether data from said one device needs to be decrypted or decompressed during transmission and whether said data needs to be subsequently encrypted or compressed during transmission to said another device, including information regarding corresponding encryption keys, and whereby, by referring to the conversion definition table, rules regarding data transfer between the plurality of logical devices can be accomplished such that security of data can be maintained as needed.