ABSTRACT

INTRODUCTION

UWCNs are constituted by sensors, sink, autonomous under vehicles.

That interact to perform specific applications such as under water monitoring.

Contd...Each sensor node is a small, energy constrained device with the ability to sense the surrounding environment.

The AUV has high mobility, deployed for applications that need mobility.

The sink (base station) behaves as an interface between the sensor nodes and the clients.

CONTENTSUnderwater wireless communication networks Characteristics and vulnerabilities of UWCNs Attacks on UWCNs and counter measures Security Requirements Research Challenges Summary Applications Conclusion

UNDER WATER WIRELESS COMMUNICATION NETWORKSRadio Waves do not propagate well Under Water due to the high energy absorption of water.

Therefore under water communications are based on acoustic links.(large propagation delays).

Acoustic channels have low bandwidth. As a result the bit error rates of acoustic channels are high ,and looses of connectivity arise. ContdUnder water wireless communication networks are particularly vulnerable to malicious attacks.

Several methods are proposed to secure under water wireless communication networks.

Schemes namely secure time synchronization, localization and routing in UWCNS

ATTACKS ON UWCNS AND COUNTERMEASURESThe different attacks possible are: Jamming Wormhole Attack Sinkhole Attack HELLO Flood Attack Acknowledgement Spoofing Selective Forwarding Sybil Attack

JAMMING

METHOD OF ATTACK:

The transmission of data packets continuously so that the wireless channel is blocked.

COUNTERMEASURES:Spread spectrum techniquesSensors can switch to sleep modeWORMHOLE ATTACK

METHOD OF ATTACK:False neighborhood relationships are created.The adversary can delay or drop packets.

COUNTERMEASURES:Estimating the direction of arrival.

SELECTIVE FORWARDING:

METHOD OF ATTACK: Drop certain messages instead of forwarding to hinder routing.

COUNTERMEASURES:

Multipath routingauthentication

SINKHOLE ATTACK:

METHOD OF ATTACK: Malicious node attempts to attract traffic from a particular area towards it.

COUNTERMEASURES:

Geographical routingAuthentication of nodes exchanging routing information

HELLOFLOOD ATTACK:

METHOD OF ATTACK:

A node receiving aHELLO packet from a malicious node interpret that the adversary is a neighbour.

COUNTERMEASURES:

Bidirectional link verificationACKNOWLEDGMENT SPOOFING

METHOD OF ATTACK:

A malicious node overhearing packets sent to neighbour nodes can use this information to spoof acknowledgments

COUNTERMEASURES:

EncryptionSYBIL ATTACK

METHOD OF ATTACK:

An attacker with multiple identities can pretend to be in many places at once.

COUNTERMEASURES:

Position verification.

RESEARCH CHALLENGESThe security issues and open challenges for 1.Secure time synchronization 2.Secure localization 3.Secure Routing

SECURE TIME SYNCHRONISATIONTime synchronization is essential in many underwater applications such as synchronized sensing tasks.

The open research issues are:

1.Because of high and variable propagation delays of UWCNs, the time required to synchronize nodes should be investigated.

2.Efficient and secure time synchronization

SECURE LOCALISATIONLocalization is a very important issue for data tagging. It can also help in making routing decisions.

Localization schemes can be classified into: 1. Range-based schemes (i) Anchor-based schemes (ii) Distributed positioning schemes 2. Range-free schemes

The open research issues.. Effective cryptographic techniques are required to prevent injection of false information.

Algorithms able to determine the location of sensors even in the presence of Sybil and wormhole attacks have to be developed.

Techniques to identify malicious or compromised anchor nodes and to avoid false detection of these nodes are required.

Secure localization mechanisms able to handle node mobilitySECURE ROUTINGRouting is specially challenging in UWCNs due to the large propagation delays, the low bandwidth, the effort of battery refills of underwater sensors, and the dynamic topologies.

Therefore, routing protocols should be designed to be energy-aware, robust, scalable and adaptive.

Spoofing, replaying or altering the routing information affects routing

The open research issues are There is a need to develop reputation-based schemes

Quick and powerful encryption and authentication mechanisms against outside intruders

Sophisticated mechanisms should be developed against insider attacks

ADVANTAGESIt avoids data spoofing.

It avoids privacy leakage.

It minimizes communication and computational cost.

Maximizes the battery power by preserving the power of the sensors

DRAWBACKSChallenging in UWCNs due to the large propagation delays, low bandwidth, the effort of battery refills of underwater sensors, and the dynamic topologies.

Schemes are challenging as they do not work well in mobile environments.

APPLICATIONSCoastal Surveillance systems

Search and rescue operations

Contd.Oceanographic studies

Marine Archaeology

CONCLUSIONAs UWCNs have huge scope of applications in sensitive military and intelligence fields, security of the network is of paramount importance.

This report gives an overall view of the unique characteristics of UWCNs, some of the common threats and attacks faced by such a network and some solutions to overcome these problems

The main research challenges related to secure time synchronization, localization and routing have also been surveyed.

REFERENCESMari Carmen Domingo, Securing Underwater Wireless Communication Networks, IEEE Wireless Communications, February 2011.

Zaihan Jiang, Underwater Acoustic Networks Issues and Solutions, International Journal of Intelligent Control And Systems, Vol. 13, No. 3, Page No. 152-161, September 2008.