An ad hoc network is a collection of wireless nodes dynamically forming a temporary network without any infrastructure and centralized control, its operations are usually performed in a fully distributed manner. This means every node is carrying out an equal role and sharing its job evenly.
From this point providing security support for large Adhoc wireless networks is a big challenge due to
their unique characteristics, such as mobility, dynamic node joins and leaves using a wireless connection.
According to the connected nature of nodes in ad hoc, a trust relationship must exist to transmit their packets between them. Security demands that all nodes must be authenticated before the transmitting process start. In this research, we propose an authentication module to assist in building a trust
relationships between ad hoc nodes by using Kerberos protocol including Kerberos in ad hoc net prevents of identity forgery, mutual authentication between nodes, and secure distribution of messages between nodes in a particular net, and between different nets belong to other realms.