Central to this project is the modeling of the basic building blocks (i.e., devices) that compose the complex structures that implement security primitives PUFs, POKs, TRNGs, COAs, etc.

While in most security analyses the composition as a whole may not be treated as a black box, one may assume that each device can be treated as a black box, i.e., only its input/output behavior described as a statistical process is known to an attacker. The goal of this task is to model a device as a parameterized statistical process that takes as input its internal state, environmental conditions (e.g., voltage/temperature variations), challenge bits, and other inputs, and produces an output with possible side information. The statistical process that describes each device in these general terms is known to the adversary while the specific parameterization that differs from device to device is not known to the adversary (in practice, only a general statistics on the parameter selection is public).

This modeling framework will be achieved through two sub tasks:

Task A.1: Black Box Statistical Device Modeling:
The need for a precise device model that expresses the device’s input and output behavior based on a set of hidden parameters (caused by manufacturing variability) is twofold. First, it should be assumed that a general device model to be public knowledge: Anyone can spend research time and effort to develop a general device model, so, in general an adversary has access to such a model. Hence, an accurate device model represents adversarial knowledge and is needed in this project security analysis. Second, in order to design complex structures composed of devices, it is necessary to understand what compositions will propagate device properties such as reliability, robustness, security, etc. To model the input/output behavior of a complex composition, an accurate model of its component devices is needed.

Task A.2. Device Characterization
In this task, a set of physical and environmental properties (P & E) will be identified and investigated on how they impact security primitives in building blocks (i.e., nano-devices), BBSDM, and the compositions.