Trust based Multicast routing in Mobile Ad hoc Network

Trust based Multicast routing in Mobile Ad hoc

Network

November 11, 2011

Vadakkumuri V Aboobacker [Aboo]

Student Id: 41418220

Supervisor: Dr. Rajan Shankaran

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Trust based Multicast in Mobile Ad hoc Networks

Macquarie UniversityITEC810 Project - Semester 2, 2011

Summary2

Introduction

Multicast in MANET

Trust in MANET

Trust management frameworks in MANET

Trust based multicast frameworks

A new trust based extension for MAODV multicast protocol

Conclusion and future directionsTrust based Multicast in Mobile Ad hoc Networks

Introduction

Multicast in MANET

Trust in MANET


Trust based multicast


Conclusion and future directions

3


Introduction

Background4

Characteristics Self organising

Self configuring Distributed and cooperative network operations

No fixed infrastructure Highly dynamic multi-hop topology

Applications Battlefields Emergency rescue services Business conferences or school class rooms


Project aim

Identify the routing related challenges in MANETs, especially with multicast routing Security and efficiency

Identify the solutions available to address these challenges Trust management frameworks Trust based multicast routing

Design a trust based extension to MAODV multicast routing protocol

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Significance6

Increasing popularity of MANETs Evolution from a military based networks in to

commercial space

A lot of research issues have surfaced due to peculiar characterises of MANETs, especially in the area of routing

Multicast is a very important feature required in MANETs Optimize node and network utilization

Various researches are focused around unicast routing Only little attention has been given to trust based

multicast


Analysis methodology7

Study the security challenges in unicast and multicast routing in MANET Multicast techniques Analyse MAODV multicast protocol in depth

Study the trust management frameworks in MANETs General trust Importance of trust in MANETs Various trust management frameworks

Apply trust based schemes to multicast routing Study existing security based and trust based

solutions Used AODV and MAODV as candidates for analysis

Propose a new scheme for trust based multicast


Introduction

Multicast in MANET

Trust in MANET





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Multicast in MANET

Multicast in MANET9

Traditional Link State and Distance Vector protocols are not directly applicable Dynamic topology changes

Varying link and node conditions Nodes moving, joining and leaving

Co-operative routing Every node is a potential router!

Multicast techniques Reactive and proactive protocols Mesh based and tree based Focus on a tree based protocol – Multicast

Adaptive On demand Distance Vector Protocols (MAODV)


Multicast Adaptive On demand Distance Vector protocol (MAODV)10

A tree based approach All the nodes in the multicast groups are in

a multicast tree

Only one path exists between two nodes of the tree

The goal is to graft a branch to the nearest (least hop count) leaf node of the tree

Tree management is a distributed approachTrust based Multicast in Mobile Ad hoc Networks


Group leader First node in the multicast group A node may assume the leadership if no route reply

(RREP) received for a multicast group Timeout and retries

Maintains the route sequence number for the multicast group Periodic Group Hello messages

Repairing portioned groups and broken links

Features: Reactive protocol Hop count for route selection process (Distance

Vector) Broadcast id to avoid duplicate protocol messages Route sequence number to indicate freshness of a

routeTrust based Multicast in Mobile Ad hoc Networks


Route discovery: Broadcasts RREQ protocol message to every

neighbours Neighbours check their routing table

Replies (RREP) if a route exists Otherwise re-floods the request to its

neighbours Nodes record the route back to the source

node to relay RREP message back to source The requested node receives many routes

from different neighbouring nodes Chooses the best route using hop count and

uses MACT to establish only one branch to the nearest leaf node



RREQ

RREQ

RR

EQ

RREQ

RREQ

RREQ

RR

EQ

RREQ

RR

EQ

MCAST

RREP

RREP

RREP

RREP

RR

EP

RREP

RREP

MCAST

New network node initiating route discovery

Group leader

Node acting as route alone

Existing group member + router Link

Branch of the multicast tree

A regular network node

Security related Challenges in Multicast

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Similar security threats as in fixed networks DoS, unauthorized disclosure, unauthorized modification,

non-repudiation, unauthorized access, etc

Certain attacks are more aggravated, especially DoS attacks due to: Co-operative routing (every node is a router) Highly dynamic network topology Resource limited nodes Unreliable communication media

Counter measures are difficult: Protection should be implemented in every node Limitation on node resources No trusted third party

Basis of key management Difficult to do authentication and authorizationTrust based Multicast in Mobile Ad hoc Networks

Introduction

Multicast in MANET

Trust in MANET





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Trust in MANET

Trust in MANET16

The network nodes are generally unpredictable Due to varying node and link conditions Malicious intentions including selfish nodes No central administration

Trust can be viewed as an expectation on how the node going to behave in future Networking functions such as routing are simplified if the

nodes are predictable (good or bad)

Trust is can be considered as an ingredient to solve security related challenges in MANETs Achieve co-operation The more trustworthy a node is, the more reliable it

isTrust based Multicast in Mobile Ad hoc Networks

Trust in MANET – Problems with Security services in MANET

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Traditional means of protection using security services: Authentication, authorization, non-repudiation,

integrity, confidentiality

Can not reliability detect node’s conditions Node movements, battery levels, noise levels, etc

Relies on a central trusted third party (certifiers and KMC)

Implementation is difficult in resource limited nodes Security services put additional burden on

network nodes

Relies on the trustworthiness of network infrastructure Physical security of routers Administration by a competent and central

autonomous body

Trust in MANET – Why?18

Identifies malicious or selfish activities of nodes Using trust management framework More trustworthy a node, the more reliable it is

Considers varying network and node conditions into account Node movements, conditions of nodes and

communication media Better for dynamic environments such as MANET

Reduces cryptographic computational requirements Better solution for resource limited nodes

Compliments security services and vice versa Many distributed key management schemes are based on

trust Robust systems can be built by combining trust and security

services.


Introduction

Multicast in MANET

Trust in MANET





19




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Requirements: Highly dynamic Selfish and malicious nodes do exist No unreasonable computational requirements Continuous, short lived and calculated online No central trusted third party

Must be a distributed approach

Predicts the nodes behaviour in future – trustworthiness Based on certain evidences such as certificates or

keys (evidence based) Based on past experiences (reputation based)Trust based Multicast in Mobile Ad hoc Networks

Trust management frameworks in MANET – Reputation based

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Most prevalent technique in MANET All nodes collect and keep historical

interactions Good and bad behaviours

Also collect opinions from other nodes

Quantify the collected evidences into trust metrics Used in decision making process such as

selection of routes Various techniques used for calculation

Simple approach: The ratio of good interactions and total interactions in a window period

Complicated approaches using statistical and probability techniques


Introduction

Multicast in MANET

Trust in MANET





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Problems with routing protocols in MANETs

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Designed mainly to take care of: Dynamic nature of the network Scalability

to be implemented in resource limited nodes

Security is an after thought!

Assumes all the nodes are: Trustworthy, properly administered and have the

capacity to perform networking functions

This assumption could be safe in traditional fixed and wireless networks (dedicated routers) Every node is a router in MANET! Trust based Multicast in Mobile Ad hoc Networks

Techniques to secure routing infrastructure - Security based AODV24

Uses signatures to protect protocol messages Uses certificates Provides authentication and integrity

Problems: Requires cryptographic computations Uses certificates but PKI is not defined Do not consider ambient route

conditions A secure node does not mean that it is

reliable! Varying conditions of link and nodes along

the path to the destination


Trust based multicast25

Uses a trust management framework

Uses trust values while admitting node to multicast group

Uses the trust value during route selection process Shortest path is not sufficient due to highly dynamic

nature of networks Trust can include ambient route conditions Trust can also include security related attributes of

the nodes along the path Trust also can be used as a decision point to re-

evaluate an existing route Trust based Multicast in Mobile Ad hoc Networks

Techniques to secure routing infrastructure – Trust based AODV26

No cryptography involved Distributed trust management approach

There are various schemes available Some assumes most network nodes are reliable Some uses only self derived node trust while others

also use recommendations from other nodes Whilst some schemes considers node trust, others

use route trust to consider the reliability of all the nodes in the path

Based on the analysis, there is room for improvement! Trust based Multicast in Mobile Ad hoc Networks

Introduction

Multicast in MANET

Trust in MANET





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A new approach for trust based MAODV multicast routing protocol28

Trust management framework Reputation based trust management Uses Node trust and route trust

Self derived and recommendations Uses confidence value

Only reliable trusts are advertised Rely on recommendations based trust if

confidence value is low Relies more on self derived trust as the

confidence value increases


Node trust29

Calculates based on recent interactions (good and bad) Used for route selection process Used for admission in to multicast tree

Node trust is the combination of self derived trust and recommendations.

Rely on recommendation based trust if confidence value is low

Relies more on self derived trust as the confidence value increases


Node trust30


Node trust31


Route trust32

Route trust Calculates based on the send vs. received packet counts

along the route Also uses the trust value of individual nodes along the

routes to derive the route trust Re-evaluates the selected routes periodically


(9) Is used initially during the initial route discover process

Route selection process33

Protocol messages RREQ, RREP are modified to include trust values

The route with highest trustworthy nodes as wells as the least hop count is selected.

Configurable weights for considering hop count and trust


Introduction

Multicast in MANET

Trust in MANET





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Conclusion35

Trust is an important concept in MANETs due to the co-operative nature of the network (Infrastructure less and self organising nature)

Security based solutions are difficult in resource limited devices and are more prone to DoS attacks

Security based approaches cannot take care of the dynamic nature of the network and varying route conditions

Trust based solutions could detect malicious nodes, selfish nodes and also to improve cooperation in the network Increases network throughput and utilization Trust could also complement security based solutions and vice

versa.

Trust based routing (unicast and multicast) is considered very ideal in MANETs to secure the routing infrastructure


Future directions36

Security should not be an after thought in designing network protocols More significance to trust based schemes

Key management is crucial for security services Centralized key management not applicable More attention to distributed key management is required

Compared to fixed networks, MANET is very far from being popular Challenges associated with MANETs will continue to be hot

research topic for years to come

Fine tuning of proposed trust management framework and trust based multicast Simulations and experiments


Introduction

Multicast in MANET

Trust in MANET





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Questions and discussions


Trust based Multicast routing in Mobile Ad hoc Network

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