Patent ID: 7814318
Filing Date: 2010-10-12
Classification: G06F

Abstract:
1. A method for managing files which facilitates key management for encrypted files, the method comprising: maintaining file-class keys at a file manager, wherein each file-class key is associated with a different class of files, wherein every file in the class of files is encrypted and decrypted using a same file-class key, and wherein each file in the class of files is associated with an expiration time; if a file belongs to a class of files, ensuring that whenever the file is stored or updated in non-volatile storage that the file is encrypted with an associated file-class key for the class of files, wherein the file-class key is stored in encrypted form in non-volatile storage; wherein storing the file-class key in encrypted form in non-volatile storage involves storing multiple encrypted copies of the file-class key, wherein each copy is encrypted with a different key-manager-file-class key managed by a different key manager, and wherein decrypting a copy of the file-class key involves causing one of the key managers to decrypt the encrypted file-class key using the corresponding key-manager-file-class key; and causing a class of files to become permanently unreadable by causing an associated file-class key, which can be used to decrypt the class of files, to become permanently unreadable.