1. Identity-based secure collaboration in wireless ad hoc networks
Jianping Pan, Lin Cai, Xuemin Shen, Jon W.Mark
University of Victory & University of Waterloo
(Computer Networks, 2007)
Jinho Seol

2. Identity-Based Secure Collaboration in Wireless Ad Hoc Networks
Contents
Introduction
Security
Voluntary collaboration
Evaluation
Conclusions
Identity-Based Secure Collaboration in Wireless Ad Hoc Networks

3. Identity-Based Secure Collaboration in Wireless Ad Hoc Networks
Introduction [1/2]
Wireless ad hoc networks
Self-organized systems without any preexisting, fixed communication infrastructures
Identity-Based Secure Collaboration in Wireless Ad Hoc Networks

4. Identity-Based Secure Collaboration in Wireless Ad Hoc Networks
Introduction [2/2]
Challenges in ad hoc networks
Guarantee that they exchange information with intended peers
Assurance that the confidentiality, integrity, and authenticity of information exchange
(as packets are relayed by peers without preestablished trustworthiness)
Measures to stimulate and compensate favorable collaborations
Benefit from secure collaboration for entire system among selfish peers
Security & Voluntary collaboration
Identity-Based Secure Collaboration in Wireless Ad Hoc Networks

5. Identity-Based Secure Collaboration in Wireless Ad Hoc Networks
Security [1/4]
Security threats & Challenges
Pairwise trustworthiness among all peers is impractical
Autonomous peers can eavesdrop or corrupt replayed data
Malicious peers can impersonate other peers
If there are colluding peers, entire system is down
Traditional PKI approach
Feasible but problematic
No online authorities that can always be involved
Per-hop level security (not only end-to-end)
Identity-Based Secure Collaboration in Wireless Ad Hoc Networks

6. Identity-Based Secure Collaboration in Wireless Ad Hoc Networks
Security [2/4]
Identity-based cryptography(IBC)
A form of public-key cryptography(PKC)
Public-key of an entity can be derived from its identity directly
Key generation center(KGC)
Unique public as identity(ex. Network address or address)
Master keys are generated and kept secretly
Private keys computed
Proposed in smart card at first
KGC
Random Seed
Key
Identity
Identity-Based Secure Collaboration in Wireless Ad Hoc Networks

7. Identity-Based Secure Collaboration in Wireless Ad Hoc Networks
Security [3/4]
Public key cryptosystem
Identity based cryptosystem
Message
Encryption
Channel
Decryption
Message
Private Key
Public Key
Directory
CAs
Seed
Message
Encryption
Channel
Decryption
Message
Identity
Key
Key Generator
Seed
Identity-Based Secure Collaboration in Wireless Ad Hoc Networks

8. Identity-Based Secure Collaboration in Wireless Ad Hoc Networks
Security [4/4]
Public key signature scheme
Identity based signature scheme
Message
Encryption
Channel
Decryption
Message
Private Key
Public Key
Directory
CAs
Seed
Message
Encryption
Channel
Decryption
Message
Identity
Key
Key Generator
Seed
Identity-Based Secure Collaboration in Wireless Ad Hoc Networks

9. Voluntary Collaboration [1/3]
Acceptable when peers are genuine, collaborative, and under the control of a single authority j j b b b b i k i c k b a b c
Identity-Based Secure Collaboration in Wireless Ad Hoc Networks

10. Voluntary Collaboration [2/3]
Peer strategies in ad hoc networks
Voluntary
Collaborative
Solely selfish
Challenges
If peers are selfish?
ex> battery-powered peers
Solution
Collaboration strategies – The profitability principle
Solely selfish peers may want to be collaborative
Identity-Based Secure Collaboration in Wireless Ad Hoc Networks

11. Voluntary Collaboration [3/3]
The profitability principle
Voluntary peers are compensated
A peer can join the network with a certain amount of credit
Destination payer model is used
2 types of expense to get data
Cost to obtain
Cost to move j i k
Identity-Based Secure Collaboration in Wireless Ad Hoc Networks

12. Identity-Based Secure Collaboration in Wireless Ad Hoc Networks
Evaluation [1/4]
Network topology
Peer demography
Identity-Based Secure Collaboration in Wireless Ad Hoc Networks

13. Identity-Based Secure Collaboration in Wireless Ad Hoc Networks
Evaluation [2/4]
Remaining energy in different demographic scenarios
Identity-Based Secure Collaboration in Wireless Ad Hoc Networks

14. Identity-Based Secure Collaboration in Wireless Ad Hoc Networks
Evaluation [3/4]
General demographic remaining energy & obtained info
Identity-Based Secure Collaboration in Wireless Ad Hoc Networks

15. Identity-Based Secure Collaboration in Wireless Ad Hoc Networks
Evaluation [4/4]
System performance metrics
Identity-Based Secure Collaboration in Wireless Ad Hoc Networks

16. Identity-Based Secure Collaboration in Wireless Ad Hoc Networks
Conclusions
Identity-based secure collaboration
IBC
To ensure information confidentiality, integrity, and authenticity
The profitability principle
To encourage selfish peers to collaborate
Summary
Peer collaboration is essential part of wireless ad hoc networks
Peer authentication methods using IBC
Participation as collaborative peers
Identity-Based Secure Collaboration in Wireless Ad Hoc Networks

17. Identity-Based Secure Collaboration in Wireless Ad Hoc Networks
Extra
Concerns
KGC
Security problem
Evaluation
The general demographic scenario is not realistic
Identity-Based Secure Collaboration in Wireless Ad Hoc Networks