Computer Science Department
School of Computer Science, Carnegie Mellon University
Security for a High Performance Commodity Storage Subsystem
Howard B. Gobioff
This dissertation analyzes a variety of access control schemata that exist in current distributed storage systems. Motivated by the analysis, I propose a basic cryptographic capability system that is flexible enough to efficiently meet the requirements of many distributed storage systems. Next, I explore how a variety of different mechanisms for describing a set of NASD objects can be used to improve the basic capability system. The result is a new design based on remote execution techniques. The new design places more access control processing at the drive in order to deliver increased performance and functional advantages. Based on the performance limitations of software cryptography demonstrated in a prototype implementation of a network attached storage device, I propose and evaluate an alternative to standard message authentication codes. This allows storage devices to pre-compute some security information and reduces the amount of request-time computation required to protect the integrity of read operations. Finally, I discuss the availability of cryptographic hardware, how much is required for a network attached storage device, and the implications of adding tamper-resistant hardware to a storage device.