Kemal AkkayaWireless & Network Security 1 Department of Computer Science Southern Illinois University Carbondale CS 591 – Wireless & Network Security Lecture 11: Ad hoc Networks Security Dr. Kemal Akkaya

Kemal AkkayaWireless & Network Security 2 Ad Hoc Networks  In addition to Wireless LANs we will focus on Ad hoc Network Security  Two types of Ad Hoc networks:  Mobile Ad hoc Networks – MANETs  Wireless Sensor Networks – WSNs  We have mentioned these networks before  More Details and Comparison in this lecture

Kemal AkkayaWireless & Network Security 3  Formed by wireless hosts which may be mobile  No pre-existing infrastructure  Routes between nodes may potentially contain multiple hops  Nodes act as routers to forward packets for each other  Node mobility may cause the routes change A B C D A B C D What is MANET?

Kemal AkkayaWireless & Network Security 4  Advantages: low-cost, flexibility  Ease & Speed of deployment  Decreased dependence on infrastructure  Applications  Military environments soldiers, tanks, planes  Civilian environments vehicle networks conferences / stadiums outside activities  Emergency operations search-and-rescue / policing and fire fighting Applications of MANETs

Kemal AkkayaWireless & Network Security 5 Sensors A prototype Mote sensor developed at Univ. of California at Berkley (RF MHz 10kbps, 20 meter range) A wireless sensor node developed at Millennial Net Inc.  What is a sensor?  Small device that can sense information around itself  The sensing circuitry measures ambient conditions and transforms them into an electric signal  Collected reports are sent (broadcasted) via radio transmitter

Kemal AkkayaWireless & Network Security 6 Wireless Sensor Networks (WSNs) Sink node  Organizes and control sensors to perform a job assigned by command node  Interacts with command node via long range communication channel Command node  Performs mission planning  Arbitrate jobs among sensors  Fuses data Sensor node  Probes it surroundings  Short range communication  Programmable transmission range  Capable of operating in an active mode or a low-power stand-by mode

Kemal AkkayaWireless & Network Security 7 Sensor Network in a Lab

Kemal AkkayaWireless & Network Security 8 Characteristics of Wireless Sensor Networks (WSN)  Small and sheer number of nodes  Difficult to assign addresses to thousands of nodes  Data from multiple sources to a single sink  Tree-based routing architecture  Redundant data  Spatial: From the same region  Temporal : Similar times  Fixed Sensors  They do not move  Fixed or mobile sinks  Some applications may have moving sinks  Constant Data  Depending on the application: High volume or less  Constraints  Energy, bandwidth, memory etc.

Kemal AkkayaWireless & Network Security 9 Benefits and Applications of Wireless Sensor Networks  Environmental Monitoring  Great Duck Island  Volcano Eruptions  Structural Health Monitoring  Bridges, Buildings etc.  Military Applications  Target tracking  Border Control  Intrusion detection  Planetary Applications  NASA’s Mars mission  Biosensors and Healthcare Monitoring  Implantable sensors for human body  Chance to collect huge amount of and accurate data  Less cost in terms of hardware, software and labor when compared to wired solutions  Easy setup of the network  No need to deal with cables anymore  Various type of information gathering  Temperature, humidity, acoustics, motion, light, pressure, seismic, image, video, chemical, biological sensors are available

Kemal AkkayaWireless & Network Security 10 MANET vs WSN  Less energy, bandwidth, CPU constrained  All nodes mobile  Less number of nodes  Each node can communicate with any node  No redundant data  May have burst data  Severely constrained in terms of energy, bandwidth, memory, CPU and storage  Sensors are fixed  Huge number of nodes  All data flow to a sink  Significant Redundancy in Data  Constant Data most of the time

Kemal AkkayaWireless & Network Security 11 Security Challenges in Ad Hoc Networks  No inherent physical protection  physical connections between devices are replaced by logical associations  sending and receiving messages do not need physical access to the network infrastructure (cables, hubs, routers, etc.)  Broadcast communications  Wireless usually means radio, which has a broadcast nature  Transmissions can be overheard by anyone in range  Anyone can generate transmissions, which will be received by other devices in range which will interfere with other nearby transmissions  Thus it is easier to implement jamming, eavesdropping, injecting bogus messages, and replaying previously recorded messages

Kemal AkkayaWireless & Network Security 12 Security Challenges in Ad Hoc Networks  Limited resources (e.g., CPU cycles, battery supply)  Susceptible to Denial of Service attacks  Can not execute computation-heavy algorithms like public key algorithms  Simpler and energy-efficient mechanisms are needed  Dynamic Topologies and Membership  Nodes may leave and join  Any malicious or misbehaving node can create hostile attack or keep all other nodes from providing any service  Trust relations may change  No trustworthy third party  Key management is an issue  No online CA or Trusted Third Party is difficult to deploy security mechanisms such as public key encryption or digital signature

Kemal AkkayaWireless & Network Security 13 Security Wired network vs. Ad hoc network  Wired network  Attacker must gain physical access to wired link  Attacker has to sneak through firewalls or security gateways  Ad hoc network  Infrastructureless network does not have an effective defense  Wireless attacks may come from all directions  Every node can encounter with an attacker  Issues to be considered in this class for Ad hoc Networks  Key Management  Secure Routing  Trust  Intrusion Detection

Kemal AkkayaWireless & Network Security 14 Summary Any solution must satisfy the following requirements ：  The cost of implementing the security mechanism must not be prohibitive.  The security mechanism must be simple to implement and maintain.  There should be minimum changes to existing standards and products.  The solution should be scalable.  The solution should be upgradeable.