Abstract: In a data processing system, stored data that is essential to a given data processing operation, such encryptographic key generation, is tamper proof in that if such data is altered, processing of the altered data is inhibited upon retrieval.

Abstract: In a system for transferring data between a host device and a target recording medium, a buffer interface control unit includes a host direct memory access (DMA) unit for transferring data from the host unit to a buffer memory. The host DMA unit accesses a first set of prescribed noncontinuous buffer memory storage locations to store the data transferred from the host unit in a predetermined buffer format that includes additional sets of prescribed storage locations interspersed with the first set of data storage locations for the storage of error code characters pertaining to the data. The host DMA unit also transfers error correction code characters pertaining to the data to one of the additional sets of prescribed storage locations. The buffer interface control unit further includes a target DMA unit for transferring data from the buffer memory to a write interface unit.