This tutorial paper explores the mechanics of protecting computer-stored information from unauthorized use or modification. It concentrates on those architectural structures--whether hardware or software--that are necessary to support information protection. The paper develops in three main

Fully automated radiosynthesizers are continuing to be de-veloped to meet the growing need for the reliable production of PET tracers made under current good manufacturing practice guidelines. There is a current trend toward supporting kitlike disposable cassettes that come preconfigured for particular tracers, thus eliminating the need for cleaning protocols between syntheses and enabling quick transitions to synthe-sizing other tracers. Though ideal for production, these systems are often limited for the development of novel tracers because of pressure, temperature, and chemical compatibility consid-erations. This study demonstrated the versatile use of the ELIXYS fully automated radiosynthesizer to adapt and produce 8 different 18F-labeled PET tracers of varying complexity. Methods: Three-reactor syntheses of 2-deoxy-2-18F-fluoro-

A conventional camera captures blurred versions of scene information away from the plane of focus. Camera systems have been proposed that allow for recording all-focus images, or for extracting depth, but to record both simultaneously has required more extensive hardware and reduced spatial

outperform an inverted list engine. Our analysis further identifies two significant causes that differentiate the performance of the IR and RDBMS implementations: the join algorithms employed and the hardware cache utilization. Our results suggest that contrary to most expectations, with some modifications

Dynamic information flow tracking is a hardware mechanism to protect programs against malicious attacks by identifying spurious information flows and restricting the usage of spurious information. Every security attack to take control of a program needs to transfer the program’s control

. An adversary can intro-duce a Trojan designed to disable or destroy a system at some future time, or the Trojan could leak confi-dential information and secret keys covertly to the ad-versary. Trojans can be implemented as hardware modifications to ASICs, commercial-off-the-shelf (COTS) parts, microprocessors

chassis. Our approach requires low-cost hardware modifications and relatively simple software support. We evaluate our architecture through both prototyping and simulation. For workloads representing 132 servers from nine different enterprise deployments, we show significant power budget reductions

-level modifications, is transparent to programmers, and requires only trivial additional hardware support. SLE can provide programmers a fast path to writing correct high-performance multithreaded programs.

of their descendants allows several simultaneous attacks on the computation time required by the problem. These approaches range from algorithmic changes (replacing an O(N’) algorithm with an algorithm whose time-complexity is believed to be O(N log N)) to data structure modifications, code-tuning, and hardware

Conventional security exploits have relied on overwriting the saved return pointer on the stack to hijack the path of execution. Under Sun Microsystem 's Sparc processor architecture, we were able to implement a kernel modification to transparently and automatically guard applications