Trust model based self organized routing protocol for secure ad hoc networks l.jpg
This presentation is the property of its rightful owner.
Sponsored Links
1 / 44

Trust Model Based Self-Organized Routing Protocol For Secure Ad Hoc Networks PowerPoint PPT Presentation


  • 146 Views
  • Uploaded on
  • Presentation posted in: General

Trust Model Based Self-Organized Routing Protocol For Secure Ad Hoc Networks. Li Xiaoqi CSE Department, CUHK 29/04/2003. Outline. Introduction to Ad Hoc Networks Motivation and Design Goals Trust Model for Ad Hoc Networks Trusted Self-Organized Routing Protocol Conclusion

Download Presentation

Trust Model Based Self-Organized Routing Protocol For Secure Ad Hoc Networks

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Trust model based self organized routing protocol for secure ad hoc networks l.jpg

Trust Model Based Self-Organized Routing Protocol For Secure Ad Hoc Networks

Li Xiaoqi

CSE Department, CUHK

29/04/2003


Outline l.jpg

Outline

  • Introduction to Ad Hoc Networks

  • Motivation and Design Goals

  • Trust Model for Ad Hoc Networks

  • Trusted Self-Organized Routing Protocol

  • Conclusion

  • Research Plan and Future Work


Now come to l.jpg

Now Come to:

  • Introduction to Ad Hoc Networks

  • Motivation and Design Goals

  • Trust Model for Ad Hoc Networks

  • Trusted Self-Organized Routing Protocol

  • Research Plan and Future Work

  • Conclusion


What is ad hoc network l.jpg

What is Ad Hoc Network

  • A kind of network without fixed infrastructure such as base stations or access points, which performs communications through wireless media

  • Wireless applications in:

    • Military Operations

    • Disaster Relief

    • Meeting Room Setup for Conference

    • Personal Area Networking


Characteristics of ad hoc networks l.jpg

Characteristics of Ad Hoc Networks

  • No fixed infrastructure

  • Each node is a router

  • Multi-hop routing by nodes cooperation

  • Self-organization nature

  • High mobility

  • Prone to be attacked


Routing protocols for ad hoc networks l.jpg

Routing Protocols for Ad Hoc Networks

  • AODV:

    -Ad Hoc On-Demand Distance Vector Protocol

  • DSR:

    -The Dynamic Source Routing Protocol

  • DSDV:

    -Destination-Sequenced Distance Vector Protocol


Overview of aodv l.jpg

Overview of AODV

  • Discover routes when needed

  • Mainly two types of routing messages:

    • RREQ: Route Request

    • RREP: Route Reply

  • Fixed-length messages

  • Only one mutable field: Hop Count


Route discovery in aodv l.jpg

Route Discovery in AODV

RREQ

Broadcast

S

D

RREP

RREP


Now come to9 l.jpg

Now Come To:

  • Introduction to Ad Hoc Networks

  • Motivation and Design Goals

  • Trust Model for Ad Hoc Networks

  • Trusted Self-Organized Routing Protocol

  • Conclusion

  • Research Plan and Future Work


Security requirements in ad hoc networks l.jpg

Security Requirements in Ad Hoc Networks

  • Confidentiality

  • Authenticity

  • Integrity

  • Availability

  • Non-repudiation

  • Access Control


Attacks to ad hoc networks l.jpg

Attacks to Ad Hoc Networks


Common solutions for security l.jpg

Common Solutions for Security

  • Often assume

    • A trusted authority to issue certificates.

    • A centralized server to monitor the networks.

    • A secret association between certain nodes.

  • Disadvantages

    • Destroy the self-organization nature of ad hoc networks.

    • Limit the mobility of nodes.

    • Single point of failure

    • Less of efficiency and availability


Self organized solutions for security l.jpg

Self-Organized Solutions for Security

  • Properties

    • Authenticate each other in a self-organized way

    • Often issue certificate of a public key by nodes cooperation

    • Often need node monitoring mechanism

  • Disadvantages

    • Need at least k neighbors to cooperate

    • Monitoring mechanism is difficult to implement and is performance-consuming


Current issues in ad hoc networks l.jpg

Current Issues in Ad Hoc Networks

  • Lack of security consideration

  • Centralized server or trusted third parties destroy the self-organization nature

  • Pure cryptographic solutions bring high overhead

  • Current self-organized solutions lose flexibility


Our solutions and design goals l.jpg

Our Solutions and Design Goals

  • Design a suitable decentralized trust model that can be used for the security solutions of ad hoc networks.

  • Apply this trust model to design a flexible self-organized key management scheme.

  • Apply this trust model to design a secure and flexible self-organized routing protocol with lower overhead.

  • Demonstrate the principle of the trust model and the security advantages of the resulting ad hoc networks.


Now come to16 l.jpg

Now Come To:

  • Introduction to Ad Hoc Networks

  • Motivation and Design Goals

  • Trust Model for Ad Hoc Networks

  • Trusted Self-Organized Routing Protocol

  • Research Plan and Future Work

  • Conclusion


Trust model for ad hoc networks l.jpg

Trust Model for Ad Hoc Networks

  • Overview of trust theory

    • Trust is a basic aspect of human life.

    • Trust is regarded as a measurable variable.

    • Trust theory has been applied into the fields of E-Commerce

  • Organization of nodes in ad hoc networks is similar as human society

    • Apply trust theory to secure ad hoc networks


Previous trust models l.jpg

Previous Trust Models

  • Direct and recommendation trust model

    • Continuous value to represent trust

    • Basis of many other trust models

  • Recommendation protocol model

    • Focus on the exchange of trust information

  • Dempster-Shafer Theory based model

    • Upper and lower bound pair to represent trust

    • Trust matrix to represent trust relationship

    • Combine two matrices using Dempster-Shafer theory


Previous trust models con d l.jpg

Previous Trust Models (Con’d)

  • Model using Fuzzy Logic

    • Trust matrix to represent trust relationship

    • Fuzzy logic to verify transactions

    • Fuzzy logic to combine trust matrices

  • Model using Subjective Logic

    • Use Opinion to represent trust

    • Opinion includes belief, disbelief, uncertainty

    • Combine trust using subjective logic


Comparison of trust models l.jpg

Comparison of Trust Models

  • Single trust value vs. Opinion

    • Opinion with belief, disbelief and uncertainty can express more information

  • Fuzzy logic vs. Subjective logic

    • Fuzzy logic operates on certain measures about fuzzy propositions

    • Subjective logic operates on uncertain measures about crisp propositions


Comparison of trust models con d l.jpg

Comparison of Trust Models (Con’d)

  • Shafer theory vs. Subjective logic

    • Both introduce uncertainty

    • No need to set upper or lower bounds of trust described in Shafer theory


Design issues of trust model l.jpg

Design Issues of Trust Model

  • Definition of Trust

  • Representation of Trust

  • Combination of Trust

  • Exchange of Trust Information


Our trust model l.jpg

Our Trust Model

  • Use ‘Opinion’ to define and represent trust

  • Combine trust opinions using subjective logic

  • Define a trust recommendation protocol to exchange trust information


Definition and representation of trust l.jpg

Definition and Representation of Trust

  • Opinion: a three-dimensional metric

  • The opinion about the trustworthiness of x, denoted by ωx , is the triple defined by:

    • b(x) represent belief: probability of believing x.

    • d(x) represent disbelief: probability of disbelieving x

    • u(x) represent uncertainty: probability of uncertainty about x’s trustworthiness


Definition and representation of trust con d l.jpg

Definition and Representation of Trust (Con’d)

  • Property of Opinion:

    • b, d, u is in [0,1]

    • b+d+u = 1

  • Opinion ωx (0.4,0.1,0.5) can be represented in the right figure.


Combination of trust l.jpg

Combination of Trust

  • Discounting Combination

    • Combine trusts along one path

    • Combine

  • Consensus Combination

    • Combine trusts from several paths

    • Combine


An example of combining trust l.jpg

A want to know

B’s trustworthiness

An Example of Combining Trust


Trust recommendation protocol l.jpg

Trust Recommendation Protocol

  • Exchange trust information

  • Three types of message:

    • TREQ: Trust Request

    • TREP: Trust Reply

    • TWARN: Trust Warning

  • Message structure


Our trust model vs subjective logic trust model l.jpg

Our Trust Model vs. Subjective Logic Trust Model

  • Simplify the representation of trust, which is more suitable for ad hoc networks

  • Propose a trust recommendation protocol to exchange trust information

  • Handle the dynamic of trust which is not mentioned in subjective logic


Now come to30 l.jpg

Now Come To:

  • Introduction to Ad Hoc Networks

  • Motivation and Design Goals

  • Trust Model for Ad Hoc Networks

  • Trusted Self-Organized Routing Protocol

  • Research Plan and Future Work

  • Conclusion


Assumption of our trusted routing protocol l.jpg

Assumption of Our Trusted Routing Protocol

  • Ability to recover node’s neighbors.

  • Reliability of broadcasting one-hop messages

  • Uniqueness of node’s ID

  • Capability of monitoring behaviors of one-hop neighbors

  • Key management has been done before


Node model l.jpg

Node Model

  • One node has an opinion about others

  • Each node maintains a trust table. For Example, A’s trust table is:

  • Initial opinion of a node in others’ eyes is (0,0,1)


General framework l.jpg

C

r

y

p

t

o

g

r

a

p

h

i

c

R

o

u

t

i

n

g

D

i

s

c

o

v

e

r

y

a

n

d

M

a

i

n

t

e

n

a

n

c

e

T

r

u

s

t

T

r

u

s

t

T

r

u

s

t

R

e

c

o

m

m

e

n

d

a

t

i

o

n

U

p

d

a

t

i

n

g

C

o

m

b

i

n

a

t

i

o

n

T

r

u

s

t

e

d

R

o

u

t

i

n

g

D

i

s

c

o

v

e

r

y

P

r

o

t

o

c

o

l

A

L

g

o

r

i

t

h

m

A

l

g

o

r

i

t

h

m

a

n

d

M

a

i

n

t

e

n

a

n

c

e

T

r

u

s

t

M

o

d

e

l

T

r

u

s

t

e

d

R

o

u

t

i

n

g

P

r

o

t

o

c

o

l

B

a

s

i

c

A

O

D

V

R

o

u

t

i

n

g

P

r

o

t

o

c

o

l

General Framework


Cryptographic technologies l.jpg

Cryptographic Technologies

  • Use cryptographic schemes to do routing in the beginning of this network

  • Adopt ideas in SAODV [42]

    • Digital signature: authenticate the non-mutable fields of the messages

    • Hash chains: secure the only mutable field ‘hop count’


Overview of trusted self organized routing protocol l.jpg

Overview of Trusted Self-Organized Routing Protocol

  • Effective when trust relationships have been established among most nodes

  • Based on AODV routing protocol

  • Criteria to determine whether a node can be trusted or not is:

    • belief≥0.5, disbelief<0.5, uncertainty<0.5

  • Nodes cooperate to decide a opinion


Trusted routing discovery l.jpg

Trusted Routing Discovery


Trust update algorithm l.jpg

Trust Update Algorithm

  • Each value in a opinion is logically divided into 5 levels. Every 0.25 is one level.

  • Successful verification for ten times:

    • belief+=0.25, disbelief-=0.125, uncertainty-=0.125

  • Failed verification for each time:

    • belief-=0.125, disbelief+=0.25, uncertainty-=0.125

  • No verification during expiry time

    • belief-=0.375, disbelief+=0.125, uncertainty+=0.25


Trust update algorithm con d l.jpg

Trust Update Algorithm (Con’d)

  • If in opinion A to B,

    belief<0 or disbelief>1

    • Opinion(AB) will be changed to (0,1,0)

    • Node A broadcast this opinion using TWARN message

    • Neighbors will re-calculate the opinion using trust combination algorithm

    • B will be denied from A’s communication


Trusted key management l.jpg

Trusted Key Management

  • Use trust model into key management

  • Advantages:

    • Self-organization

    • Flexible: no limitation of at least k neighbors

    • Lower overhead


Analysis l.jpg

Analysis

  • Performance is increased

    • No need to perform cryptographic calculations for every packet lower overhead

  • Security is enhanced

    • Combination of trust model, cryptographic schemes and monitor mechanism

  • More reasonable and flexible

    • Good nodes who become bad will be denied from network eventually

    • Bad nodes who turn to good will be allowed accessing network again soon


Now come to41 l.jpg

Now Come To:

  • Introduction to Ad Hoc Networks

  • Motivation and Design Goals

  • Trust Model for Ad Hoc Networks

  • Trusted Self-Organized Routing Protocol

  • Conclusion

  • Research Plan and Future Work


Conclusion l.jpg

A promising idea to apply trust model to secure ad hoc networks

Node uses ‘opinion’ to judge if another node is trustable

Nodes cooperate to obtain a more accurate opinion

Trusted routing protocol is

Self-organized

Lower-overhead

More reasonable

More secure

More flexible

Conclusion


Research plan and future work l.jpg

Research Plan and Future Work

  • A better trust combination algorithm

  • A better way to apply trust model into key management

  • Study monitor or intrusion detection issues

  • Improve trusted routing protocol to make it prevent or stand more attacks

  • A detailed simulation evaluation using NS-2 or Glomosim simulators


Slide44 l.jpg

Q&A

Thank you !


  • Login