Cryptographic transformations are a fundamental building block in many security applications and protocols. To improve performance, several vendors market hardware accelerator cards. However, until now no operating system provided a mechanism that allowed both uniform and efficient use of this new type of resource.We present the OpenBSD Cryptographic Framework (OCF), a service virtualization layer implemented inside the operating system kernel, that provides uniform access to accelerator functionality by hiding card-specific details behind a carefully designed API. We evaluate the impact of the OCF in a variety of benchmarks, measuring overall system performance, application throughput and latency, and aggregate throughput when multiple applications make use of it.We conclude that the OCF is extremely efficient in utilizing cryptographic accelerator functionality, attaining 95% of the theoretical peak device performance and over 800 Mbps aggregate throughput using 3DES. We believe that this validates our decision to opt for ease of use by applications and kernel components through a uniform API and for seamless support for new accelerators. Furthermore, our evaluation points to several bottlenecks in system and operating system design: data copying between user and kernel modes, PCI bus signaling inefficiency, protocols that use small data units, and single-threaded applications. We identify some of these limitations through a set of measurements focusing on application-layer cryptographic protocols such as SSL. We offer several suggestions for improvements and directions for future work. We provide experimental evidence of the effectiveness of a new approach which we call operating system shortcutting. Shortcutting can improve the performance of application-layer cryptographic protocols by 27% with very small changes to the kernel.

Abstract Networks of the future will be characterized by a variety of computational devices that display a level of dynamism not seen in traditional wired networks. Because of the dynamic nature of these networks, resource discovery is one of the fundamental problems that must be solved. While resource discovery systems are not a novel concept, securing these systems in an efficient and scalable way is challenging. This paper describes the design and implementation of an architecture for access‐controlled resource discovery. This system achieves this goal by integrating access control with the Intentional Naming System (INS), a resource discovery and service location system. The integration is scalable, efficient, and fits well within a proxy‐based security framework designed for dynamic networks. We provide performance experiments that show how our solution outperforms existing schemes. The result is a system that provides secure, access‐controlled resource discovery that can scale to large numbers of resources and users. Copyright © 2004 John Wiley & Sons, Ltd.