Patent ID: 7596696

Claim:
A method for managing files which facilitates making the files permanently unreadable, comprising: encrypting a file with a key K at a file manager; storing the encrypted file in non-volatile storage; storing the key K in a key database in volatile storage at the file manager; encrypting the key database, wherein encrypting the key database involves encrypting the key database with a key X and encrypting the key X with a key PN to form an encrypted key; and storing the encrypted key database in non-volatile storage, wherein storing the encrypted key database in non-volatile storage involves storing the encrypted key and the encrypted key database in non-volatile storage; wherein a key that can be used to decrypt the encrypted key database is maintained by a key manager, and is not maintained in non-volatile form by the file manager, whereby if the file manager crashes, losing the contents of local volatile storage, the file manager must interact with the key manager to decrypt the encrypted key database.