KAIST

Decentralized key generation scheme Decentralized key generation scheme for cellular-based heterogeneous for cellular-based heterogeneous

wireless ad hoc networkswireless ad hoc networks

23年 4月 19日

임 형 인

Ananya Gupta, Anindo Mukherjee, Bin Xie and Dharma P. Agrawal

University of Cincinnati

Journal of Parallel and Distributed Computing 2007

ContentsContents

Introduction

Background

Decentralized key generation schema

Security and Performance Analysis

Conclusion

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Introduction (1/4)Introduction (1/4)

Traditional MANET(Mobile Ad hoc NETwork)Purely consist of mobile nodes

Absence of the centralized authority

Many problems with secure key generationBecause no prior trust relationships

Solution is pre-distribution of secure key

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Introduction (2/4)Introduction (2/4)

Cellular-based MANET in realityThe cellular mobile has more than one cellular medium

Bluetooth, Wi-Fi, Infrared, etc medium of MANET

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Cellular infra

Bluetooth Wi-Fi Infrared

Introduction (3/4)Introduction (3/4)

Necessity of MANET in realityDirect communication between mobiles is cheaper

Cheaper than communication through Cellular infrastructure

Take advantages of cellular infrastructure to MANETUtilizing a cellular network for key management

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Authenticatio

n

from Cellu

lar-infra

How to get security?

Authentication

from Cellular-infra

Introduction (4/4)Introduction (4/4)

In this paperPropose “Decentralized key generation scheme” for MANET

Multiple BS(Base Station)

Minimize intervention

Scalability of key generation and distribution

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Polynomial key schemeTwo variable for one symmetric calculation

BackgroundBackground

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1 2

1. Input x

2. Exchange identifier

1. Input x

3. Input y

3. Input y

4. Same value (secret key)

Symmetric Property

Decentralized key generation Decentralized key generation schema (1/5)schema (1/5)

Extended form of polynomial keyFour variable for two symmetric calculation

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Mobile

peer

Base Station

peer

Decentralized key generation Decentralized key generation schema (2/5)schema (2/5)

Cellular infrastructure for key management

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Decentralized key generation Decentralized key generation schema (3/5)schema (3/5)

Group-based polynomialPolynomial exchange between Base Stations

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Decentralized key generation Decentralized key generation schema (4/5)schema (4/5)

Polynomial for MSDistributing polynomials to Mobiles

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Decentralized key generation Decentralized key generation schema (5/5)schema (5/5)

Pairwise direct message exchange between Mobiles

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Entity ID

Base Station i

Mobile a

Entity ID

Base Station j

Mobile b

Security analysis (1/2)Security analysis (1/2)

Hazard of K-degree polynomial keyCompromise entire secret key by compromising ≥K nodes

Hazard of the polynomial key in this paper

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Possible to calculateoriginal functionCompromise more

than K nodesOnce compromise entire network

Entity type Compromise condition

Compromised

Base Station ≥ K

Mobile ≥ K2

Mobile ≥ K

a BS, b MS aK+b ≥ K2

Security analysis (2/2)Security analysis (2/2)

Security comparison (Yi Cheng et al.)Bulletproof at sensor node capture attack (while <K)

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Polynomial scheme

Performance analysis (1/3)Performance analysis (1/3)

Routing overhead in key exchange

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Performance analysis (2/3)Performance analysis (2/3)

Average latency during the initial key exchange

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Performance analysis (3/3)Performance analysis (3/3)

Key storage overhead comparison (Yi Cheng et al.)

Constant and low storage overhead with whatever size

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Polynomial scheme

ConclusionConclusion

Propose a novel method for cellular-based MANET

MS can enjoy the same trust in MANETTrust in MS is derived from backbone cellular network

Easy key distribution by polynomial key schemeFunction key distribution and exchanging identifier

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