Electrical and Computer Engineering ETDs

Publication Date

Summer 7-15-2020


Software routines that deviate from the original algorithm’s goal due to a perturba- tion agent is a phenomenon that has been observed for a long time now. From unin- tended executions on flight control computers during the dawn of space exploration, passing through hardware Trojans tampering in corporate security, to sensitive med- ical equipment compromised to the point of changing the amount of delivered drug, the time intervals, and the reported biomedical measured data, such intrusions are a major risk challenging society. In this dissertation, a computer under perturbation is modeled by a hybrid sys- tem that captures the digital nature on the discrete part, and the interaction of the perturbation signal with the hardware on the continuous part, like extreme electro- magnetic interference (EEMI) on logic circuits. From this point, the dissertation develops in three directions. First, we develop a testbed simulation environment of a 4-bit processor with the ability to take perturbation signals both in time and space. Second, we formulate of mathematical models of the computer logic that take perturbation signals as inputs. And third, we use reachability theory to access how far the perturbation propagates through hardware to cause an exploitable deviation in software execution. We formulate two modifications to the traditional Hamilton- Jacobi-Evans equations (HJE). A diffusion term is added to the original HJE and we also include the second-order terms of the Taylor expansion of the optimality principle.


Reachability Software Execution Computing Systems


AFOSR Grant FA9550-15-1-0171

Document Type




Degree Name

Electrical Engineering

Level of Degree


Department Name

Electrical and Computer Engineering

First Committee Member (Chair)

Edl Schamiloglu

Second Committee Member

Gregory Heileman

Third Committee Member

Chaouki Abdallah

Third Advisor

Sameer Hemmady