Pre-Grant Publication Number: 20100246827
Filing Date: March 27, 2009Priority Date: March 27, 2008
Inventors: Kristin Estella Lauter, Mihir Bellare, Josh Benaloh, Melissa E. Chase, Erik J. Horvitz, Chris Demetrios Karkanias
Assignee(s): Microsoft Corporation
Current U.S. Classification: 380, 380/278000, 380/045000
Abstract

The claimed subject matter relates to architectures that can construct a hierarchical set of decryption keys for facilitating user-controlled encrypted data storage with diverse accessibility and hosting of that encrypted data. In particular, a root key can be employed to derive a hierarchical set of decryption keys and a corresponding hierarchical set of encryption keys. Each key derived can conform to a hierarchy associated with encrypted data of the user, and the decryption capabilities of the decryption keys can be configured based upon a location or assignment of the decryption key within the hierarchy. The cryptographic methods can be joined with a policy language that specifies sets of keys for capturing preferences about patterns of sharing. These policies about sharing can themselves require keys for access and the policies can provide additional keys for other aspects of policy and or base-level accesses.