Scalable security for large, high performance storage systems

Abstract

New designs for petabyte-scale storage systems are now capable of transferring hundreds of gigabytes of data per second, but lack strong security. We propose a scalable and efficient protocol for security in high performance, object-based storage systems that reduces protocol overhead and eliminates bottlenecks, thus increasing performance without sacrificing security primitives. Our protocol enforces security using cryptographically secure capabilities, with three novel features that make them ideal for high performance workloads: a scheme for managing coarse grained capabilities, methods for describing client and file groups, and strict security control through capability lifetime extensions. By reducing the number of unique capabilities that must be generated, metadata server load is reduced. Combining and caching client verifications reduces client latencies and workload because metadata and data requests are more frequently serviced by cached capabilities. Strict access control is handled quickly and efficiently through short-lived capabilities and lifetime extensions.We have implemented a prototype of our security protocol and evaluated its performance and scalability using a high performance file system workload. Our numbers demonstrate the ability of our protocol to drastically reduce client security latency to nearly zero. Additionally, our approach improves MDS performance considerably, serving over 99% of all file access requests with cached capabilities. OSD scalability is greatly improved; our solution requires 95 times fewer capability verifications than previous solutions.