Patent ID: 7873828

Claim:
A method for writing encrypted data to an Enterprise System Connection (ESCON) tape system, the method comprising: receiving from a computer over a first ESCON link a command to write a data block of specified size to the ESCON tape system; requesting data constituting the data block from the computer in sub-blocks, each sub-block being smaller in size than the data block when the data block is larger than a sub-block; compressing and encrypting each sub-block to produce a corresponding compressed and encrypted sub-block; and transmitting to the ESCON tape system over a second ESCON link the compressed and encrypted sub-blocks using a series of chained-data write operations, the transmitted compressed and encrypted sub-blocks forming a compressed and encrypted data block on a tape of the ESCON tape system; wherein the compressed and encrypted data block includes fixed-size block metadata including information about the compressed and encrypted data block, each compressed and encrypted sub-block is immediately preceded by associated fixed-size sub-block metadata including information about that compressed and encrypted sub-block, and each compressed and encrypted sub-block except for a last compressed and encrypted sub-block is immediately followed by the sub-block metadata associated with a next compressed and encrypted sub-block, the sub-block metadata associated with a first compressed and encrypted sub-block immediately following the block metadata.