This paper discussed about a challenging task of providing security in Ad-hoc networks and also discussed about attacks, security mechanisms and different aspects of security services.  Attacks in ad-hoc networks are classified into active and passive attacks, depends on whether the networks normal operation is disrupted or not. 


A wireless network can be viewed highly, so requires more sophisticated and efficient security mechanisms. External attacks are occurred by nodes which are not part of the network.  Encryption and firewalls can prevent external attacks.

Internal attacks are occurred by nodes which are part of the network. It is difficult to detect internal attacks and the impact of these attacks is severe when compared to that of external attacks.  Integrity refers the information passed on two different nodes has not been altered during the transmission. An user identity can be determined by a network service, Authenticity. 

The two important mechanisms used for data integrity and authentication are message encryption and digital signatures.  Symmetric and Asymmetric are two popular data encryption mechanisms.  The secret key is used for both encryption and decryption in symmetric mechanism where as public and private keys are used for encryption and decryption respectively in asymmetric mechanism.  

Digital code attached to a message helps to identify the sender uniquely.  The key component of most authentication schemes is digital signatures.  Some of the popular existing security mechanisms are asymmetric cryptography and one way hash functions. 


Security threats in ad-hoc networks and security objectives need to be achieved are discussed in this paper.  Ad-hoc networks are highly vulnerable to security attacks and some of applications in this network require high degree of security.  This paper discussed about existing security providing techniques and as well as new mechanisms to secure ad-hoc networks.  Along with preventing security attacks in ad-hoc networks there is also need to identify the impact of security mechanisms on the network performance.

Download  Security -Ad-Hoc Wireless Networks ECE Seminar Topic Documentation .