Survivable storage systems

Survivable storage systems must maintain data and access to it in the face of malicious and accidental problems with storage servers, interconnection networks, client systems and user accounts. These four component types can be grouped into two classes: server-side problems and client-side problems. The PASIS architecture addresses server-side problems, including the connections to those servers, by encoding data with threshold schemes and distributing trust amongst sets of storage servers. Self-securing storage addresses client and user account problems by transparently auditing accesses and versioning data within each storage server. Thus, PASIS clients use threshold schemes to protect themselves from compromised servers, and self-securing servers use full access auditing to protect their data from compromised clients. Together, these techniques can provide truly survivable storage systems.