Abstract A mobile node in a MANET must be assigned a free IP address before it may participate in unicast communications. This is a fundamental and difficult problem in the practical application of any MANET. There have been several solutions proposed, among which prophet address allocation outperforms others in terms of communication overhead, latency, and scalability. However, none of the approaches can survive attacks in an insecure environment. Although there are a few secure autoconfiguration schemes proposed, they all have some disadvantages. Based on studies of insecure scenarios, attack schemes, and our previous work, a secure autoconfiguration algorithm, namely secure prophet address allocation, is proposed in the paper. The proposed approach is able to maintain uniqueness of address assignment in the presence of IP spoofing attacks, [state pollution] attacks, and Sybil attacks. The invulnerability of the scheme is supported by both theoretical analysis and simulation results. Copyright © 2009 John Wiley & Sons, Ltd.

Security is extremely important for the deployment of a mobile ad-hoc networks (MANET) due to its openness to attackers, the absence of an infrastructure, and the lack of centralized administration. Most research efforts have been focused on secure routing protocols, the distributed certificate authority, and key distribution, while a few projects have focused on secure autoconfiguration. However, the importance of integration of a secure autoconfiguration and public-key distribution has been neglected. This paper presents a secure autoconfiguration and public-key distribution algorithm to achieve uniqueness of address allocation and secure public-key distribution when a new node joins a MANET, which provides the bootstrapping for building a distributed certificate authority (DCA) in the network where a trust relationship is absent.

Most prevalent distributed certificate authority (DCA) schemes in the MANET are based upon threshold cryptography, which is invulnerable to mobile adversaries and tolerable to missing or faulty DCA server nodes, and thus becomes the "de facto" standard for the security framework in the MANET. However, this scheme cannot defeat Sybil attacks, in which a malicious node impersonates many identities. To solve the problem, a multiple-key cryptography-based DCA scheme, namely the MC-DCA scheme, is proposed in the paper. It is invulnerable to Sybil attacks, and achieves lower communication overhead and moderate latency compared with the threshold-based scheme, which is supported by the simulation results.

Globally unique ID allocation is usually not applicable in a sensor network due to the massive production of cheap sensor nodes, the limited bandwidth, and the size of the payload. However, locally unique IDs are still necessary for nodes to implement unicast communications to save power consumption. Several solutions have been proposed for locally unique ID assignment in sensor networks. However, they bring much communication overhead, which is not desirable due to the limited power supply in a sensor node. Combined with a directed diffusion communication paradigm, a reactive ID assignment scheme with security mechanisms is proposed in this paper. It defers ID conflict resolution until data communications are initiated and thus saves communication overhead.

When compared with a fixed host that is connected to a hardwired network, a mobile nude in the MANET may change its IP address more frequently due to the deployment of autoconfiguration, global connectivity, and hierarchical addressing schemes. When an IP address changes, the performance of unicast routing protocols and real-time communications may degrade, and privacy may be compromised within the MANET. Although there have been some autoconfiguration algorithms proposed for the assignment of unique IP addresses to mobile nodes, the overhead resulting from address changes has not been carefully examined. Based on studies of the overhead caused by address change, an IP address handoff solution, which extends the unicast routing protocol and network address translation (NAT) scheme, is proposed in the paper. The proposed approach is able to offset the overhead of broken routing fabrics and on-going communications, which is supported by our analysis and a prototype implementation.

A mobile device in a MANET must be assigned a free IP address before it may participate in unicast communication. This is a fundamental and difficult problem in the practical use of any MANET. Several solutions have been proposed. However, these approaches have different drawbacks. A new IP address allocation algorithm, namely prophet allocation, is proposed in the paper. The proposed scheme may be applied to large scale MANETs with low complexity, low communication overhead, even address distribution, and low latency. Both theoretical analysis and simulation experiments are conducted to demonstrate the superiority of the proposed algorithm over other known algorithms. Moreover, the proposed prophet allocation is able to solve the problem of network partition and merger efficiently.