Storage Protection Key Generation Method for I/O Devices and Storage Controllers
Original Publication Date: 1988-Nov-01
Included in the Prior Art Database: 2005-Feb-15
This article describes a technique to prevent unauthorized access to a storage block associated with a storage controller utilizing a key associated with each block. Input/output (I/O) devices must present a key selector to the storage controller so that access authority can be determined by verification of storage access by key comparison. When an I/O device wishes to read or write storage, an address, a key selector and (possibly) data or a command are transmitted from the I/O device to the storage. The storage controller determines the key that should be used for the access by indexing into a table based on the value of the key selector. The storage controller also generates a key for the block based on the high-order bits of the storage address.