This paper describes a technique that exploits the statistical delay variations of wires and transistors across ICs to build a secret key unique to each IC. To explore its feasibility, we fabricated a candidate circuit to generate a response based on its delay characteristics. We show that there exists enough delay variation across ICs implementing the proposed circuit to identify individual ICs. Further, the circuit functions reliably over a practical range of environmental variation such as temperature and voltage.

SUMMARYThis paper describes a technique to reliably and securely identify individual integrated circuits (ICs) based on the precise measurement of circuit delays and a simple challenge-response protocol. This technique could be used to produce key-cards that are more difficult to clone than ones involving digital keys on the IC. We consider potential venues of attack against our system, and present candidate implementations. Experiments on Field Programmable Gate Arrays show that the technique is viable, but that our current implementations could require some strengthening before it can be considered as secure.

This paper develops a methodology to estimate the regional economic impacts of electricity lifeline disruptions caused by a catastrophic earthquake. The methodology is based on specially designed input-output and linear programming models. A simulation of a major earthquake in the New Madrid Seismic Zone near Memphis, Tennessee, indicates the potential production loss over the recovery period could amount to as much as 7 percent of gross regional product. Reallocation of scarce electricity across sectors could reduce the impacts substantially. Additionally, an improved restoration pattern of electricity transmission substations across subareas could reduce losses even more.

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