Secure Authentication of Multicast protocol for Ad-Hoc Networks

Abstract
multicast stream authentication and signing is an important and challenging problem.applications such astroop coordination in a combat field, situational awareness, etc.the main challenges are fourfold.first,authenticity must be guaranteed even when only the sender of the data is trusted. Second, unguaranteed connectivity to trusted authorities make known solutions for wired and single hop wireless network inappropriate.we propose an efficient Scheme, Tiered Authentication scheme for Multicast traffic (TAM) for large scale dense ad-hoc networks. TAM combines the advantages of the time asymmetry and the secret information asymmetry paradigms and exploits network clustering to reduce overhead and ensure scalability. Multicast traffic within a cluster employs a one-way hash function chain in order to authenticate the message source. Cross-cluster multicast traffic includes message authentication codes (MACs) that are based on a set of keys. Each cluster uses a unique subset of keys to look for its distinct combination of valid MACs in the message in order to authenticate the source. The simulation and analytical results demonstrate the performance advantage of TAM in terms of bandwidth overhead and delivery delay.
Index Terms—Multicast communications, message authentication, ad-hoc networks.
INTRODUCTION
THE continual advancement in wireless technologies has enabled networked-solutions for many nonconventional civil and military applications. In recent years ad-hoc networks have been attracting increased attention from the research and engineering community, motivated by applications like digital battlefield, asset tracking, air-borne safety, situational awareness, and border protection. In these network applications, it is important to devise efficient network management solutions suitable for nodes that are constrained in onboard energy and in their computation and communication capacities. In addition, the solutions must be scalable to support networks covering vast areas with a large set of nodes that communicate over many hops. These characteristics make the design and management of ad-hoc networks significantly challenging in comparison to contemporary networks. In addition, the great flexibility of ad-hoc networking comes at the price of an increased vulnerability to security attacks and trade-off would be unavoidable at the level of network management and services
Multiple factors make multicast authentication in ad-hoc networks very challenging. The issues are fundamentally due to the resource constraints and the wireless links. First, nodes have limited computing, bandwidth, and energy resources which make the overhead of basic asymmetric key-pair cryptography methods very expensive. In addition, the unstable wireless links due to radio interference cause frequent packet loss errors and require a security solution that can tolerate missed packets, as well as differentiate between packet retransmission and replay. Furthermore, the instability of the wireless links makes it unwise to rely on the continual involvement of a trusted authority in the generation and sharing of session keys since a stable connection cannot be guaranteed. On the other hand, while basic symmetric key cryptography methods are efficient, they are ineffective for multicast traffic patterns; since using a common key for all receivers will make it relatively easy to impersonate a sender by any of the receiving nodes.