Qiping Huang

A pairwise key establishment scheme for heterogeneous sensor networks

Motivated by a key agreement scheme proposed by Leighton and Micali (LM-KDS), we present a key establishment mechanism for heterogeneous sensor networks which combines random key pre-distribution schemes and LM-KDS. Using LM-KDS as its building block, proposed scheme divides nodes into groups and distributes a small number of micro key servers among nodes. This scheme consists of two phases. In the first one, some secret information is sent by the TA to every node off-line, then the TA assigns public keying material to every micro key server. In the second phase, if any pair of nodes cannot establish session key using their preloaded keying material, they may get public keying material from a micro key server through an open channel. Besides, all the public keying material preloaded in micro key servers does not need to be secret. This scheme preserves properties of LM-KDS yet takes advantage of flexibility of probabilistic approaches to yield improved resilience against node capture attacks by trading off increased communication overhead and storage complexity.

Divide-and-conquer based cooperative jamming: Addressing multiple eavesdroppers in close proximity

This paper investigates divide-and-conquer based cooperative jamming for physical-layer security enhancement in the presence of multiple eavesdroppers. Different from previous works, we consider a scenario where the eavesdroppers can be located anywhere inside the communication region of the source, no location information of the eavesdroppers is available and no constraint on the number of eavesdroppers is presupposed. The basic idea is to transmit the message in multiple rounds and exploit the helpful interference from the source and the destination to jam the eavesdroppers in close proximity. Stochastic geometry based analytic results as well as Monte Carlo simulations are presented to illustrate the achievable secrecy performances.

Storage Requirements for Key Distribution in Sensor Networks

Sensor networks are resource-constrained, which makes developing efficient key distribution scheme a challenging problem. In general, many key distribution techniques are designed to address the trade-off between limited resources and security, no key distribution technique is ideal to all the scenarios where sensor networks are used. In this paper, we primarily focus on storage requirements of several key distribution schemes in sensor networks, and obtain their lower bounds on the amount of information each user has to keep secret by modeling the key distribution schemes with an information theoretic framework.

On cooperative jamming in wireless networks with eavesdroppers at arbitrary locations

This paper investigates cooperative jamming for secure connection in wireless networks. A cooperative jamming strategy is proposed to thwart eavesdroppers anywhere in the network, even if they are located close to the source or the destination. The basic idea is to defeat eavesdroppers by a divide and conquer strategy, and exploit the helpful interference from the source and the destination to circumvent the nearby eavesdropper problem. Analysis and simulation results reveal that this strategy can enhance the secure connection probability and can tolerate any number of independent eavesdroppers provided that the number of legitimate nodes satisfies certain condition.

On key evolution over wireless channels

Noise is a powerful resource for the implementation of cryptographic primitives, especially in wireless networks. In general, a key agreement protocol is tailored to the channels and relies on the assumption that knowledge on the eavesdroppers channel is available. This is not practical. In this paper, we focus on the problem of developing key agreement schemes for secure communication across wireless channels and propose a key evolution scheme to alleviate the assumption. Keys evolve continuously based on the transmitted messages over the noisy wireless channel. Even if the eavesdroppers channel is superior to the legitimate receiver, the legitimate parties can establish secret keys. To further confuse the eavesdropper, we present a strategy for legitimate parties to send artificial noise if the eavesdropper cannot distinguish the sources of messages. Finally, we propose a k-resistant encryption scheme that can use different keys to encrypt and decrypt messages if there are no more than k bits which differ between the encryption and decryption keys.

Keying material based key pre-distribution scheme

A key pre-distribution scheme is a method by which initially an off-line trusted authority T A distributes pieces of information among a set of users. Later, each member of a group of users can compute a common key for secure communication. In this paper we present a Keying Material Based Key Pre-distribution Scheme, i.e., a group of users, using secret information preloaded in their memory and some public information retrieved from a keying material server, can compute a common key. We first formally define the keying material based key pre-distribution scheme in terms of the entropy, and give lower bounds on the amount of information each user has to keep secret. Then, we describe its applications for sensor networks.