Patent ID: 7757050

Claim:
A computer program product, including: a computer readable storage medium having computer-readable instructions for causing a computer to undertake method acts to for ensuring that data stored on rewritable storage is immutable, the method acts including: initializing selected user-addressable blocks of storage to a writable state; accepting data to be stored in specified user-addressable blocks; determining if the specified block(s) is writable; storing the accepted data to the rewritable storage; and setting the state of the specified block(s) to non-writable, wherein each user-addressable block of storage is mapped to at least one block of rewritable storage and initializing selected user-addressable blocks of storage to a writable state includes storing predetermined bit patterns into the corresponding blocks of rewritable storage such that for each selected user-addressable block of storage, the contents of the corresponding blocks of rewritable storage satisfy a predetermined mathematical relationship.