Ensuring the trustworthiness of cognitive radio networks
As the national discussion progresses on spectrum access and reallocation, many options under consideration require technological advances in cognitive radios (CR) and related dynamic spectrum access technologies. ECE’s Jung-Min “Jerry” Park is working to make sure cognitive radio devices remain trustworthy and operate within the boundaries set by regulatory frameworks.
“Cognitive radios are frequency-agile devices that can adapt their operating characteristics based on local observations,” he said. “To ensure that cognitive radios can coexist with existing wireless infrastructures and devices in a harmonious way, a number of security solutions are needed.”
One project Park and his graduate research assistants are investigating involves a tamper resistance scheme that is designed to thwart unauthorized tampering of CR software. Their approach uses code encryption and branch functions to obfuscate the target program while enabling the program to meet its performance requirements.
The challenge in developing security solutions for CR software is to operate within stringent real-time constraints, Park says. “To deal with such constraints, our scheme uses a technique called the random branch function call, which enables a user to control the tradeoff between the integrity checking frequency and the overhead,” he says.
The team is also devising a CR policy reasoner that assists in policy enforcement and carries out policy analysis and processing. The policy enforcement function monitors the channels that the CR is attempting to use and pro-actively applies enforcement mechanisms to ensure that the transmissions originating from the radio conform to the regulatory and system policy requirements. The policy analysis and processing function is based on a graph-theoretic approach and carries out conflict detection and resolution. “It is critical to avoid policy conflicts,” Park says. “They can cause serious security breaches or degrade network performance.”
Park’s work is sponsored by the NSF, SCA Technica, and Samsung Electronics.
For more information, please visit www.arias.ece.vt.edu.