Ad Hoc Networks
Security

Security issue is another important aspect concerning ad hoc networks since there is no security infrastructure. The attacks against ad hoc network can be categorized into two groups: passive and active. While the former typically involves “passive” eavesdropping, the latter one causes “active” attacks, such as modification or even deletion of exchanged data. The most common attacks in ad hoc networks are summarized below:

- DDoS (Distributed Denial of Service) – In most cases, jamming techniques to interfere with communication and thus preventing to use network.
- Impersonation – The attacker could gain access to the configuration system as super-user and could access or even destroy restricted data.
- Disclosure – The attacker can obtain confidential information by eavesdropping and take advantage from it.
- Routing attacks – Secure routing is difficult task due to ad hoc nature of network when malicious node can enter the network. The attacker can selectively drops the communication (selective forwarding attack), discard all packets (blackhole attack), etc.

The communication could be considered secured if the following is ensured:

- Availability – Guarantee that the communication would not be disrupted due to DDoS attacks.
- Authentication – Before the user is allowed to access an ad hoc network, it has to be properly authenticated (protection against impersonation).
- Confidentiality – Data packets have to be protected against any misuse.
- Integrity – It has to be guaranteed that data are not changed during their transmission.

Conventional methods for securing communication in network are through symmetric or asymmetric cryptographic keys. The asymmetric methods require a certification, which is difficult to employ in networks with lack of infrastructure such as ad hoc. Nevertheless, to guarantee safe certification process in ad hoc networks, Technique for Intrusion Resistant Ad Hoc routing algorithm (TIARA) has been proposed. Also, several secure routing protocols have been introduced to avoid most dangerous routing attacks, such as SRP (Secure Routing Protocol) based on the DST, or SAODV (Secure AODV).