Patent ID: 8090100

Claim:
A storage apparatus connected to a computer, comprising: (a) a plurality of storage devices for configuring a storage area; (b) a controller for controlling data read/write from/in the storage devices, wherein the storage area includes a first logical partition and a second logical partition, the first logical partition includes a first logical volume and the second logical partition includes a second logical volume, and the first logical partition includes a common resource that includes a first area in which pre-update data of the first logical volume is stored and a second area in which pre-update data of the second logical volume is stored; (c) an encryption/decryption unit for encrypting or decrypting data stored in said logical volumes or update data stored in said common resource; and (d) a key change unit for changing a key for encrypting or decrypting data stored in said logical volumes, and changing a key for encrypting or decrypting update data stored in said common resource based on information of said key used for data stored in said logical volumes, wherein a first encryption key is set to the first partition, and a second encryption key is set to the second partition; wherein the encryption key for the second area is changed from the first encryption key to the second encryption key, and wherein the pre-update data stored in the second area is decoded using the first encryption key and then encrypted using the second encryption key.