Security in Wireless Ad-Hoc Networks

byRaju Vemula

Outline

l Introductionl MANETl SSN

l Securityl Propertiesl Functions

l Classification of attacksl Solutionsl Conclusionl References

Introduction

lDifferent technologies have been developed for different situations and necessities.lWi-Fi technology for Wireless LAN and short range mobile access networks.lWireless USB is technology for Internet network on the go.lDifferent technologies like infrared, bluetooth are short range.

Introduction

lAd-Hoc network?l A network formed without any central administration

which consists of mobile nodes that uses a wireless interface to send packet data.

l Image from www.microsoft.com

IntroductionlThere are 2 types ad-hoc networks.

l MANET(Mobile ad-hoc network)l An autonomous system of mobile hosts connected by wireless links, often called MANET.

l Establishing survivable, efficient, dynamic communication for emergency/rescue operations.

l Disaster relief efforts.

MANET

http://www.comp.nus.edu.sg/~xuemingq/research.html

http://www.comp.nus.edu.sg/~xuemingq/research.html

Introduction

l WSN(Wireless Sensor Network)l A smart sensor network consists of a number of

sensors spread across a geographical area. l Each sensor has wireless communication capability

and sufficient intelligence for signal processing and networking.

l Military sensor networks to detect enemy movements.

l The presence of hazardous material.l Environmental sensor networks to detect and

monitor environmental changes.

Wireless Sensor Network

http://www.alicosystems.com/wireless%20sensor.htm

http://www.alicosystems.com/wireless%20sensor.htm

Properties

There is no fixed topology Wireless nodes are small they move freely in and out

of range.l E.g. Mobile phones, PDA, and wrist watches.

Limited energy

Most of the devices are operate on battery power which is limited.

Properties

Every node is a router Every node present in the network has limited amount of

communication range. All nodes out of this range can only be reached by packet forwarding.

Limited CPU/Resources In consume electronics price plays a big role. They are cheap and have limited CPU power.

Security Functions

Availability It makes sure that all the required network services are

available to the authorized users.

Authentication Authentication enables MANET to ensure the identity of

peer node that is communicating with.

Confidentiality Confidentiality ensures that some information discloses

only to the unauthorized users.

Security Functions

Data Integrity It guarantees for the information that is being

transferred.

Key and trust management Basic operations includes establishing key

exchange and update as well as secret connections.

Classification of attacks

l There are so many ways that a malicious user may attack a ad-hoc network.

l Internal attacksl Internal attacks are more difficult to protect against as the

internal nodes are trustworthy.

l External attacksl External attacks are produced by users which are not part

of network. For example one may issue an attack on company from the office next to that.

Classification of attacksl The other types of attacks are:

l Active attacksl Active attacks are caused by the users who are able to

inject the packets into the network. They are able to alter the data, interfere with the routing information and disrupt the service.

l Passive attacksl Passive attacks is mainly to steal information and to listen

on the communication in the network. These may monitor and analyze the traffic.

Classification of attacks

lAnother way to classify the attacks is by the layer at which they may occur.

l At the physical layer the malicious user may jam the communication, intercept the messages or they may just listen the messages.

l At the data link layer the attacks conducted are traffic analysis and monitoring and service disruption.

l At network layer many attacks are observed like wormhole, black hole, flooding, and resource consumption.

• Wormhole Attack:

In this attack network tunnel information to another network.At this time hacker may easily enter and do misuse inside the network.

• Black hole Attack:

It is a type of DOS(Denial of service) attack in which a router that is supposed to relay packets instead discard them.

Solutionsl“Packet Leashes: A Defense Against Wormhole Attacks in Wireless Ad Hoc Networks”, Yih-Chun Hu, Adrian Perrig, David. B. Johnson

l Protection against warm-hole attacksl Packet leashes

l Temporall The packet has an upper bound on its lifetime which restricts

the maximum travel distance.l Transmission time and expiration time of the packet.

l Geographicall The recipient of the packet is within a certain distance from

the sender.

Solutions

l“Security-Aware Ad Hoc Routing for Wireless Networks”, Seung Yi, Prasad Naldurg, Robert Kravets

l Protection against black-hole attacksl User identity is bound with an associated trust level.l For each trust level, it is used a simple shared secret to

generate a symmetric encryption/decryption keyl Provides a suite of cryptographic techniques: digital

signature, and encryption

Key Management

lKey management system must be secure, cause most cryptographic system rely on it.

l 3 types of keys in the networkl Group Key

Key for all members in group to encrypt and decrypt the data.

l Symmetric key Shared between team leader and member node of

the same group. l Shared key

Shared only by all group leaders in the network.

Conclusion

lSituations are unpredictable with the wireless networks, even with the infrastructural support.

lPresent solutions to address these attacks are not strong enough.

lKey management solutions may help, but not every time.lStill a lot of research has to be done.

References

lH Yang, H Y. Luo, F Ye, S W. Lu, and L Zhang, “Security in mobile ad hoc networks: Challenges and solutions” (2004). IEEE Wireless Communications. 11 (1), pp. 38-47.lYih-Chun Hu , Adrian Perrig, “A Survey of Secure Wireless Ad Hoc Routing”, IEEE Security and Privacy, v.2 n.3, p.28-39, May 2004.lThe Resurrecting Duckling: Security Issues for Ad-hoc Wireless Networks. Frank Stajano, Ross Anderson.lAdam Burg, “Ad hoc network specific attacks”, Seminar on Ad hoc networking: concepts, applications, and security, Technische Universitat Munchen, 2003.lCharles E. Perkins (Hrsg.). Ad Hoc Networking, Addison-Wesley 2000.

Thank you