Encryption is an important tool for security, particularly in wireless systems, where the signal is not physically constrained. However, in extremely low-power applications (e.g. RFID and sensor nets), the power required for nodes to run standard cryptographic algorithms at a high level of security can be prohibitive. In this exploratory project, the hypothesis that encryption at the physical layer can supplant encryption done digitally at higher layers in extremely low-power wireless applications is being evaluated. A novel low-power ultra-wideband (UWB) radio framework is being developed and its cryptographic security for different system parameters considered. Team expertise in digital and RF circuits allows accurate calculation of both trends and fundamental lower bounds on the power required under both standard digital cryptographic and the physical layer cryptography scheme. The research team consists of UMass faculty with expertise in ultra-wideband system design and characterization, low-power digital hardware, and low-power RF hardware, and (external) contributions from an expert in cryptography at RSA Labs. Expected results of the project include (1) the development and cryptographic assessment of the proposed UWB framework for encryption, and (2) the development of trends and lower bounds on the power required for both standard (digital) approaches and the UWB framework. The establishment of the hypothesis would have a substantial impact by providing a completely new view of how to provide encryption in low-power wireless systems. The project is also providing opportunities for graduate and undergraduate students to perform research crossing the boundaries of analog and digital circuits, communication theory and cryptography.
