Design of Self-Healing Key Distribution Schemes

A self-healing key distribution scheme enables dynamic groups of users of an unreliable network to establish group keys for secure communication. In such a scheme, a group manager, at the beginning of each session, in order to provide a key to each member of the group, sends packets over a broadcast channel. Every user, belonging to the group, computes the group key by using the packets and some private information. The group manager can start multiple sessions during a certain time-interval, by adding/removing users to/from the initial group. The main property of the scheme is that, if during a certain session some broadcasted packet gets lost, then users are still capable of recovering the group key for that session simply by using the packets they have received during a previous session and the packets they will receive at the beginning of a subsequent one, without requesting additional transmission from the group manager. Indeed, the only requirement that must be satisfied, in order for the user to recover the lost keys, is membership in the group both before and after the sessions in which the broadcast messages containing the keys are sent. This novel and appealing approach to key distribution is quite suitable in certain military applications and in several Internet-related settings, where high security requirements need to be satisfied. In this paper we continue the study of self-healing key distribution schemes, introduced by Staddon et al. [37]. We analyze some existing constructions: we show an attack that can be applied to one of these constructions, in order to recover session keys, and two problems in another construction. Then, we present a new mechanism for implementing the self-healing approach, and we present an efficient construction which is optimal in terms of user memory storage. Finally, we extend the self-healing approach to key distribution, and we present a scheme which enables a user to recover from a single broadcast message all keys associated with sessions in which he is member of the communication group

Key management for wireless sensor network security

Wireless Sensor Networks (WSNs) have attracted great attention not only in industry but also in academia due to their enormous application potential and unique security challenges. A typical sensor network can be seen as a combination of a number of low-cost sensor nodes which have very limited computation and communication capability, memory space, and energy supply. The nodes are self-organized into a network to sense or monitor surrounding information in an unattended environment, while the self-organization property makes the networks vulnerable to various attacks.Many cryptographic mechanisms that solve network security problems rely directly on secure and efficient key management making key management a fundamental research topic in the field of WSNs security. Although key management for WSNs has been studied over the last years, the majority of the literature has focused on some assumed vulnerabilities along with corresponding countermeasures. Specific application, which is an important factor in determining the feasibility of the scheme, has been overlooked to a large extent in the existing literature.This thesis is an effort to develop a key management framework and specific schemes for WSNs by which different types of keys can be established and also can be distributed in a self-healing manner; explicit/ implicit authentication can be integrated according to the security requirements of expected applications. The proposed solutions would provide reliable and robust security infrastructure for facilitating secure communications in WSNs.There are five main parts in the thesis. In Part I, we begin with an introduction to the research background, problems definition and overview of existing solutions. From Part II to Part IV, we propose specific solutions, including purely Symmetric Key Cryptography based solutions, purely Public Key Cryptography based solutions, and a hybrid solution. While there is always a trade-off between security and performance, analysis and experimental results prove that each proposed solution can achieve the expected security aims with acceptable overheads for some specific applications. Finally, we recapitulate the main contribution of our work and identify future research directions in Part V

An Efficient Self-Healing Key Distribution Scheme with Constant-Size Personal Keys for Wireless Sensor Networks

The availability of group communications over inexpensive wireless networks has facilitated new types of applications and created new security challenges. One of the security challenges is how to securely distribute session keys over wireless networks. Self-healing key distribution mechanism is an ideal countermeasure for enabling session key distribution and recovery. In order to address the issue that personal keys could not be reused if more than a threshold number of nodes are revoked in self-healing key distribution schemes, a new self-healing key distribution scheme using bilinear pairings is proposed in this paper. Another motivation for developing this new scheme is to reduce computation cost in some existing IDbased self-healing key distribution schemes. The new scheme enables users to have constant size personal keys. The personal key of each user can be reused as long as it is not disclosed. Further, any coalition of non-authorized users can not recover the session keys. That is, the scheme is collusion-free secure. The ID-based scheme can support key management by mitigating the certificate management overload. Additional advantage includes sliding-window mechanism can be applied to our scheme such that it is unnecessary to determine the number of sessions during the Setup procedure