Georgia Tech Information Processing, Communications and Security (IPCAS) Research Lab Research Lab

Cryptography and Network/Communications Security Developments in the computer and communication technology have brought a new dimension to the Information Age. Real-time exchange of information regardless of location and distance has greatly increased both the pace of business and the number of ways in which we communicate. The widespread availability and transmission of such information demands new approaches in cryptography. The objective is to build secure and reliable networks out of less secure and less reliable resource constrained devices. Our work spans the range from theoretical cryptography to applications; including significant research efforts in development of new cryptographic primitives, cryptanalysis, and applications from wireless and ad-hoc (sensor) networks to delay-tolerant (DTN) and space-time networks.



Random Key Pre-distribution


Key management is critical in establishing pairwise keys necessary for confidentiality. However, key management is difficult due to the ad-hoc nature, random deployment, intermittent connectivity, and resource limitations of the sensor nodes. The most suitable key agreement scheme is key pre-distribution for sensor networks, where some key information is placed in the nodes prior to node deployment. Recently, a number of random key pre-distribution schemes have been proposed, wherein each node before deployment is loaded by a subset of a large key pool. A shared-key discovery phase takes place during the initialization in the operation environment where every node discovers its neighbors within the wireless communication range with which it shares a key. A link exists between two nodes only if they share a key (from their stored key ring). If a link exists between two nodes, all communication on that link is secured by link encryption. This key pre-distribution scheme is extremely simple and apt for sensor-node computation and communication limitations. In this work, we propose a multivariate key pre-distribution scheme to provide the link security. We also provide a new, more accurate model and a framework in which many properties (such as connectivity, latency, average path length) of the random key management scheme and networking of sensors can be studied. Using this framework, we then study malicious attacks and optimize the scheme to minimize the threats of these attacks.