trust management in mobile ad hoc networks using a scalable maturity based model
Download
Skip this Video
Download Presentation
Trust Management in Mobile Ad Hoc Networks Using a Scalable Maturity-Based Model

Loading in 2 Seconds...

play fullscreen
1 / 49

Trust Management in Mobile Ad Hoc Networks Using a Scalable Maturity-Based Model - PowerPoint PPT Presentation


  • 131 Views
  • Uploaded on

Trust Management in Mobile Ad Hoc Networks Using a Scalable Maturity-Based Model. Authors: Pedro B. Velloso , Rafael P. Laufer , Daniel de O. Cunha, Otto Carlos M. B. Duarte, and Guy Pujolle. Paper Presentation By : Gaurav Dixit (gdixit@vt.edu). Outline. Introduction Trust Model

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Trust Management in Mobile Ad Hoc Networks Using a Scalable Maturity-Based Model' - kasa


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 management in mobile ad hoc networks using a scalable maturity based model

Trust Management in Mobile Ad Hoc Networks Using a Scalable Maturity-Based Model

Authors: Pedro B. Velloso, Rafael P. Laufer, Daniel de O. Cunha, Otto Carlos M. B. Duarte, and Guy Pujolle

Paper Presentation By : Gaurav Dixit (gdixit@vt.edu)

slide2

Outline

  • Introduction
  • Trust Model
  • Implementation
  • Results
slide3

Introduction

  • MANets - same node can work as router server client
  • Assumption of good behavior – Not true!
  • Trust needs to be measured - This paper provides one such method.
  • Applying human trust dynamics to trust calculation of nodes
  • Builds on recommendations
slide4

Trust level of a node depends on:= (previous individual experiences) + (recommendation from neighbors)

  • Benefits of trust calculation:
  • avoid sending packets to malicious nodes.
  • increased co-operation among good nodes.
slide5

Recommendations collected only from neighbors. Advantages for nodes:

  • Less storage
  • Less power requirement
  • Less processing
  • Better for changing topologies – information for entire network not required
slide6

Since, recommendations not forwarded, it is good for networks:

  • Less recommendation messages travelling in network - low traffic
  • Low energy consumption for entire network
slide7

Relationship Maturity

Similar to human trust behavior, more weightage is given to the recommendations from older neighbors.

slide8

Trust Model

  • Trust level assigned to each neighbor.
  • Trust value reflects behavior history, and thus expected future behavior.
  • Node forms opinion based on experiences.
  • Transmission of these opinions about node i are called recommendations.
slide9

Trust Model …

Recommendations compensate for lack of monitoring capabilities.

Paper defines Recommendation Exchange Protocol (REP)

slide10

Trust Model…

  • Trust level varies from 0 to 1.
  • Recommendation from C more important than that from B, because of relationship maturity.
slide11

Trust Model: Architecture

Two parts:

Learning Plan: gathers and converts information into knowledge.

Trust plan: assess trust level of each neighbor using stored knowledge and recommendations.

slide13

Trust Model: Components

  • Behavior monitor observes network, indicates new neighbors to Rec Manager, and send behavior report to Classifier.
  • Classifier sends behavior classification to Experience Calculator.
  • Trust Calculator calculates trust with inputs from experiences and recommendations.
  • Auxiliary Trust Table entries correspond to relationship maturity.
  • Trust table entries have timeout.
slide14

Trust Model: Components

  • Three operation modes:
  • Simple: Just trust table, REP optional
  • Intermediate: Simple mode plus storage of recommendations
  • Advanced: Complete system implementation.
  • Recommendation Manager implements REP.
  • All nodes are in advanced mode in this paper.
slide15

Trust level evaluation

π‘‡π‘Ž(𝑏) = (1 βˆ’ 𝛼)π‘„π‘Ž(𝑏) + π›Όπ‘…π‘Ž(𝑏)

π‘„π‘Ž(𝑏) = π›½πΈπ‘Ž(𝑏) + (1 βˆ’ 𝛽)π‘‡π‘Ž(𝑏)

Ta(b) ->Trust calculation from node a for node b

Qa(b) -> Personal Experience

Ra(b) -> Recommendations

All variables(except a & b) range from 0 to 1.

slide16

Recommendation Computation

πΎπ‘Žοƒ  subset of neighbors

𝑀𝑖(𝑏) οƒ  relationship Maturity

𝑋𝑖(𝑏) οƒ  random variable with normal distribution representing recommendation uncertainty.

𝑋𝑖(𝑏) = 𝑁(𝑇𝑖(𝑏), πœŽπ‘–(𝑏))

slide17

First Trust Values

Initial trust values can be:

Prudent : Strangers have low trust value

Optimist: High trust in new neighbors.

Moderate: Trust value between Prudent and optimist.

Fa First trust value

π‘‡π‘Ž(𝑏) = (1 βˆ’ 𝛼)πΉπ‘Ž + π›Όπ‘…π‘Ž(𝑏)

slide18

Recommendation Exchange Protocol

Only one hop neighbors considered. ( IP TTL=1)

Consists of:

TREQ: Trust Request

TREP: Trust Reply

TA: Trust Advertisement

slide19

REP

TREQ sent when nodes first meet, with IP of new neighbor as target node. Wait time tREQ before sending TREQ

TREP sent by neighbors who have target node as their neighbor, after waiting for random time period tREP

TA sent if trust level changes by threshold πœ‹

slide20

Authentication

A pair of public-private key for each node is sufficient for the system to work.

Sybil attack would not be a problem since the malicious identities are quickly found and ignored.

slide22

Nature of nodes vary from 0 (untrustworthy) to 1 (trustworthy)

A node with nature of 0.8 would do 8 good actions out of 10.

Behavior Monitor is emulated by concept of perception, which indicates probability of noticing a certain action.

Classifier (perfectly) classifies actions.

slide23

Node will decide for itself whether or not it will use behavior monitor in promiscuous mode. Required perception value and personal constraints would help in this decision.

Experience Calculator observes imin actions before calculating trust. Higher perception would result in more accurate trust level. But higher imin means higher convergence time.

Paper assumes imin =10

slide24

Results: Small networks

All nodes are at one hop distance.

Time in seconds.

Convergence at t=350 for 𝛼 = 𝛽 = 𝜏 = 0.5

slide25

Results: Small networks

Optimistic first trust strategy.

Time in minutes.

Nature set to 0.2 .

Number of neighbors varied.

slide26

Results: Small networks

Neighbors =15

Varying alpha

slide27

Results: Small networks

Perception 𝜏 is the fraction of actions a node can notice from its neighbors

Varying 𝜏

slide28

Results: MultihopMANets

Analyzing movement in more complex networks.

21 nodes with 250m transmission range, placed in 1000 m Γ— 400 m .

𝛼 = 𝛽 = 𝜏 = 0.5

First trust optimist (0.9)

Nature of nodes = 0.2

slide29

Results: Multihop …

m1 keeps 3 old neighbors

m2 has no old neighbors

slide30

Results: Multihop …

m1 keeps 3 old neighbors

m2 has no old neighbors

slide31

Results: Multihop …

Node speeds three times faster.

slide32

Results: Multihop …

Varying perception – lower perception takes longer time to converge.

slide33

Results: Relationship maturity

Node 1,8,15 go to zone F2.

Evaluating trust level of node 8 about node 20

slide34

Results: Relationship maturity

Using lower perception value(0.2)

Note that recommendations are important in low perception cases

slide35

Results: Lying Attacks

20 nodes -250m transmission range, placed in a

150 m Γ— 150m

Node 1 changes nature from 0.9 to 0.2

slide36

Results: Lying Attacks

Malicious nodes fixed at 40%

slide37

Results: Lying Attacks

Slander Attack

Node2 evaluating node1 which has nature 0.9

Pessimistic strategy (Fa=0.1)

slide38

Results: Lying Attacks

Slander Attack

Varying alpha

slide39

Results: Lying Attacks

Slander Attack

Varying perception parameter.

slide40

Results: Lying Attacks

Slander Attack

Malicious nodes lie after t=200

slide41

Results: Lying Attacks

Slander Attack

Malicious nodes identification time varying

slide42

Results: Lying Attacks

Slander Attack

Malicious nodes identification time varying

slide43

REP

  • To reduce number of messages sent across network:
  • TREQ is sent once containing multiple target nodes, using timer based approach.
  • TREP instead of sending once per request, implemented as broadcast – this saves 85%
  • TREP implemented, additionally, with timer, saves 99% messages.
  • TA implemented with a threshold to reduce its occurrence.
slide45

REP

Changing the value of Trust threshold(πœ‹)

slide46

REP

Changing the value of Trust threshold(πœ‹) and its impact on trust levels.

slide47

Discussion

  • Using smart timers in suppressing redundant messages scales well in large networks, reducing overhead for trust management by 85 to 99%.
  • Increasing value of Ξ± improves the trust model efficiency, since we can use already derived results (by neighbors) in the form of recommendations.
slide48

Conclusion

  • Flexible trust evaluation model proposed based on concept of human trust, which uses recommendations and relationship maturity.
  • Recommendation Exchange Protocol (REP) proposed.
  • Model highly scalable – since only neighbors consulted.
  • Model tolerates 35 % liars
  • Trust level error reduced by 50% by using relationship maturity parameter.
ad