A destructive-read memory is one that the process of reading the memory
causes the contents of the memory to be destroyed. Such a memory may be
used in devices that are intended to acquire data that may have
associated usage restrictions, such as an expiration date, usage count
limit, or data access fee for the acquired data. Typically, to enforce
usage restrictions, and protect against theft, complex and often costly
security techniques are applied to acquired data. With destructive-read
memory, complex and costly security is not required for stored data. In
one embodiment, a write-back mechanism, which may employ security, is
responsible for enforcing usage restrictions. If the write-back mechanism
determines continued access to acquired data is allowed, then it writes
back the data as it is destructively read from the memory.