Patent ID: 7995758
Filing Date: 2011-08-09
Classification: H04L

Abstract:
1. A method comprising: generating an original symmetric encryption key useable to encrypt and decrypt information; generating from the original symmetric encryption key a family of symmetric encryption keys useable to encrypt and decrypt information, the symmetric encryption keys of the family having a relationship such that a descendent key of the family is derivable from each key that is an ancestor of the descendent key in the family; and rolling over a key used in securing information, said rolling over comprising providing a next symmetric encryption key of the family in an order opposite that of an order of key generation; wherein said rolling over is performed using a hardware processor; and wherein the family of symmetric encryption keys is used in a document control system to secure documents, the method further comprising synchronizing offline access information with a client, the offline access information comprising a key from the family of symmetric encryption keys.