Mobile ad-hoc network is a relatively new innovation in the field of wireless technology. These types of networks operate in the absence of fixed infrastructure, which makes them easy to deploy at any place and at any time. The absense of any fixed infrastructure in mobile ad-hoc networks makes it difficult to utilize the existing techniques for network services, and poses number of various challenges in the area. Typical challenges include routing, bandwidth constraints, security and power.

Routing can be defined as a mechanism of information exchange between two hosts in a network. It plays an important role to ease communication between different parties within the network. There are various proposed routing solutions for mobile ad-hoc networks. As I discussed in the previous article, some of these solutions are table-driven, on-demand, geographical, geographical multicast and multicast. Most of these solutions mainly focus on routing and do not concentrate much on other related issues, such as security.

Security is one of the important aspects of this technology and it needs some serious attention. Users within the network want their communication to be secure. As current mobile ad-hoc networks do not have any stick security policy, this could possibly lead active attackers to easily exploit or possibly disable the mobile ad-hoc network. That would be bad.

Security goals in mobile ad-hoc networks are reached through cryptographic mechanisms such as public key encryption or digital signature. These mechanisms are backed by centralized key management where a trusted Certificate Authority (CA) provides public key certificate to mobile nodes in order to develop mutual trust between nodes. Any disturbance with the Certificate Authority can easily affect the security of the entire network.

Mobile ad-hoc networks are highly dynamic; topology changes and link breakage happen quite frequently. Therefore, we need a security solution which is dynamic, too. Any malicious or misbehaving nodes can generate hostile attacks. These types of attacks can seriously damage basic aspects of security, such as integrity, confidentiality and privacy of the node. Current ad-hoc routing protocols are completely insecure. Moreover, existing secure routing mechanisms are either too expensive or have unrealistic requirements.

Security requirements for ad-hoc routing protocols includes:

• Certain discovery, meaning the route should always be found if it exits between two nodes;
• Isolating misbehaving nodes, making sure misbehaving nodes should always be identified and isolated from routing; and
• Location privacy, protecting information about node location and network structure.