A Security Framework with Trust Management for Sensor Networks

Zhiying Yao, Daeyoung Kim, Insun LeeInformation and Communication University (ICU)

Kiyoung Kim, Jongsoo JangElectronics and Telecommunications Research

Institute(ETRI)Korea

Speaker: Kangwoo Lee

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Contents Contents

Motivation

Trust Management Based Security Framework Architecture Trust Management Component Network I/O Application Description Component Security Response Component

Example Scenario

Conclusion

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MotivationMotivation

■ Sensor network applications (e.g. monitoring safety, tracking environmental pollutants) need security at design time

■ Existing research efforts■ Focus on specific security fields, such as secure routing or

intrusion tolerance■ Main solutions recur to cryptographic algorithms, and are lacking

the complementary tool for managing trust

■ Proposed solution■ An effective security solutions from a system architectural view■ Trustworthy relationship can be evaluated locally to guide node

behavior

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Solution IllustrationSolution Illustration

AB

CD

Local node

Neighboring node of local node

Radio range

Monitor range (promiscuous mode)

Receipt of packet

Sensor Field

Logically assess neighboring nodes trustworthiness

Gather available network knowledge

Manage (store & update) the trust value of neighboring node

Securely take network action (routing, intrusion detection…)

Monitor of packet

AB

CD

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Security FrameworkSecurity FrameworkArchitectureArchitecture

We consider a general sensor network case

One base station n nodes

The architecture running locally gives nodes the abilities

Appropriate to different application requirements

Collect traffic actively or passively

Assess the trustworthiness of their neighboring nodes

Guide network action

Security Response

Network I/O

Trust Management Application Description

ReliabilityAnalysis

SecureRouting

IntrusionTolerance

IntrusionDetection

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Security FrameworkSecurity Framework Application Description Application Description

ComponentComponent

Used to set application-dependent parameters considering nature of sensor networks

Security related information, such as: Key management scheme Hash function used Message authentication code length

Trust level (Trust Regulation Table)

Weight and adjustment factors used in trust evaluation procedure

Trust Level Description Range1 Very Low trust (0,r1]2 Low trust [r1,r2)

4 High trust [r3,1)3 Medium trust [r2,r3)

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Security FrameworkSecurity Framework Network I/O Network I/O

Responsibility: Receive incoming packets Send outgoing packets Control the rate of incoming and outgoing packets Pass required information for trust evaluation

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Security FrameworkSecurity Framework Trust Management Component –1 Trust Management Component –1

A localized trust model Recommendation-based trust Trust-based recommendation

Give an individual node the ability to estimate its local environment and take action to carry out its network duty

A set of logical computation to get a numerical trust value

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Security FrameworkSecurity Framework Trust Management Component –2 Trust Management Component –2

Entities Defined judge : performs evaluation suspect : the adjacent

neighbor of the judge and will be evaluated

juries : maintain the trust value of the same suspect with the judge and send it out periodically or intentionally

Trust relationship not symmetric

If A trust B, B maybe not trust A, where A and B are mutually neighboring nodes.

time-evolving Need be updated upon

receipt of new interactive communication or new recommendations.

CB

A

Judge

Suspect

Jury

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Security FrameworkSecurity Framework Trust Management Component –3 Trust Management Component –3

Trust Evaluation Based on the localized trust model Two kinds of knowledge are

needed personal reference

direct interaction with the suspect reference

reputation sent by the juries

Trust value Deduced from the trust

evaluation procedure Represented by real numbers,

between 0 and 1 Indicate the extent of trust the

judge may have in the suspect

Parameter Assigned Trust ValueComposition

Personal Reference

Reference

Context

Trust Intention

(Trust Value)

Conceptual Trust Model

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Security FrameworkSecurity Framework Trust Management Component –4 Trust Management Component –4

Personal Reference Parameters about

cryptographic operations Represent the security

mechanisms used Can disclose attacks

(e.g. message forgery and modification)

Parameters about nodes’ interactive behavior

Reflect nodes availability Can reveal attacks (e.g.

dropping and denial-of- service)

Personal Reference

(Tpr(i))

Cryptographic Operation

Checking Packet (T*cp(i))

Checking Packet (Tcp(i))

Interactive Behavior

Availability (Tav(i))

Ordering(Tor(i))

Authentication & Integrity(Tai(i))

Confidentiality (Tco(i))

Responsibility(Tre(i))

Positivity(Tpo(i))

Cooperative Checking(Tcoo(i))

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Security FrameworkSecurity Framework Trust Management Component –5 Trust Management Component –5

Reference Reference generation

Recommendation protocols Active protocol– reference request Anti-active protocol– abnormal personal

reference report

Reference computation trust-based recommendation

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Security FrameworkSecurity Framework Trust Management Component – 6 Trust Management Component – 6

Context Maintain weighted values, passed from parameter

database Deliver necessary parameters to personal reference and

trust value computation procedure

Trust value Weighted summation between the personal reference and

reference

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Security FrameworkSecurity Framework Security Response Component Security Response Component

Integrate the mostly existing security research directions in WSN

Using available trustworthiness and a lightweight trust policy Refer to recommendation protocol

Perform appropriate network activities based on the available trust relationship

Reliability analysis, secure routing, intrusion detection, and intrusion tolerance

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Security FrameworkSecurity Framework Example Scenario –1 Example Scenario –1

We give an example to show the secure routing path selection between base station and node D as an example

Define the routing selection metric as unit trust value in consideration of both security and energy-savings together, notated as uT. Each possible path holds an uT, which can be expressed as:

between and Base Stationhopcount between and Base Station

T DuT

D

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Security FrameworkSecurity Framework Example Scenario –2 Example Scenario –2

BSI

K

NL

J

MD

Trust Level Description Range1 Very Low Trust (0, 0.2)2 Low Trust [0.2, 0.5)3 Medium Trust [0.5, 0.7)4 High Trust [0.7, 1.0)

Trust Level Regulation Table

Node I J K L M N D ...Black 0 0 0 1 0 0 0 ...TrustValue 0.78 0.67 0.64 0.17 0.62 0.65 0.61 ...

Node Status Lookup Table On BS

Destination Routing Path HopCount UTD (I,K,N) 4 0.52D (J,L) 3 0.28D (J,M) 3 0.43

Routing Information Table on BS

Destination Next Hop Black HopCount Trust ValueBS N 0 4 0.69BS L 1 3 0.54BS M 0 3 0.83

Routing Information Table on Node D

Communication Path Information Table

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ConclusionConclusion

An complete security architecture from system view

Adaptive to different application requirements

Make good use of available network knowledge

Deduce trustworthy relationship based on localized trust model

Execute network action efficiently due to the available evidence

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Thanks for Listening !!