Patent ID: 8726044

Claim:
A method comprising: in response to a storage controller of a storage system including a primary storage device and a cache storage device receiving a read request from a host for data stored on primary storage device to which the storage controller is directly connected within the storage system and that is a non-volatile storage device, determining by the storage controller whether the data is stored on the cache storage device to which the storage controller is directly connected within the storage system, that is for the primary storage device, and that is a volatile storage device having a lesser capacity and that is more quickly accessed than the primary storage device; in response to the storage controller determining that the data is not stored on the cache storage device, retrieving, by the storage controller, a first encrypted version of the data from the primary storage device, the first encrypted version of the data encrypted in accordance with a first encryption-decryption approach; decrypting, by the storage controller, the first encrypted version of the data in accordance with the first encryption-decryption approach to generate an unencrypted version of the data; sending, by the storage controller the unencrypted version of the data to the host; encrypting, by the storage controller, the unencrypted version of the data in accordance with a second encryption-decryption approach that is selected to be less processing intensive and that takes less time to perform than the first encryption-decryption approach in consideration of the cache storage device being faster than the primary storage device, to generate a second encrypted version of the data, the second encryption-decryption approach selected to be less secure than the first encryption-decryption approach in consideration of the cache storage device being volatile whereas the primary storage device is non-volatile; and storing, by the storage controller, the second encrypted version of the data on the cache storage device.