Non-volatile storage device with forgery-proof permanent storage option

摘要

The invention is related to non-volatile storage devices. The invention proposes a non-volatile storage device comprising a storage unit, means for receiving an access change indication and means for changing access to said storage unit in response to said access change indication wherein access prior to reception of said access change indication is such that data can be stored in said storage unit and already stored data can be altered and access after said access change is such that at least some of the already stored data is unalterable but still can be read wherein access to said at least some of the already stored data is irreversible after access change in response to receiving said access change indication. This combines the advantages of permanent, forgery-proof storage with the advantages of erasable storage.