1. Amar B. Patel , Shushan Zhao
Assignment #1
Protecting Privacy in Mobile Ad-hoc Networks
Amar Bahadur Patel , Shushan Zhao
October 23rd ,2007
School of Computer Science
University of Windsor
Wednesday, January 16, 2019Wednesday, January 16, 2019
Amar B. Patel , Shushan Zhao

2. Amar B. Patel , Shushan Zhao
Note
Due to small time of presentation we will not discuss all the details of the assignments#1
Wednesday, January 16, 2019Wednesday, January 16, 2019
Amar B. Patel , Shushan Zhao

3. Outline of the Presentation
Introduction
Back ground study
Privacy threats in MANET,s
Overview of a MANET system with Privacy Protection
A Basic Scheme to Implements the System
Analysis and Improvements of the Scheme
Conclusion
Wednesday, January 16, 2019Wednesday, January 16, 2019
Amar B. Patel , Shushan Zhao

4. Amar B. Patel , Shushan Zhao
Introduction
In a mobile ad hoc network (MANET),nodes join or leave the network freely, and the nodes may move on a consistent basis.
the network does not have a fixed structure and topology. Moreover, the nodes communicate via wireless radio frequency channel that is exposed to all adversaries.
Due to these specific characteristics of MANETs, security and privacy face much difficulty in this environment.
Wednesday, January 16, 2019Wednesday, January 16, 2019
Amar B. Patel , Shushan Zhao

5. Amar B. Patel , Shushan Zhao
Background study
A great deal of research in literature has focused on providing confidentiality, integrity, and authenticity of data in MANETs, but privacy and anonymity remains an open problem.
Jiang proposed to prevent traffic analysis in ad hoc networks by using traffic padding, i.e., generating dummy traffic into the network
This approach did not aim to hide the identifiers of communicating nodes and so cannot completely prevent traffic analysis.
They also explored the use of mixes in ad hoc networks by designing a mix discovery protocol that allows communicating nodes to choose mix nodes at run time. The second approach is not an anonymous routing protocol and also vulnerable to the compromise of mix nodes.
Some previous papers also discussed about designing anonymous communication protocols for MANETs.
The essence of anonymous communications is to hide sender and/or receiver's identities from outside observers. As a result, adversaries cannot correlate eavesdropped traffic information to actual network traffic patterns so that traffic analysis attack can be efficiently defeat.
Wednesday, January 16, 2019Wednesday, January 16, 2019
Amar B. Patel , Shushan Zhao

6. Amar B. Patel , Shushan Zhao
Problem Continue…….
Zhang propose a scheme for anonymous communication in MANETs.
The scheme is based on an anonymous neighborhood authentication protocol that allows neighboring nodes to authenticate each other without revealing their identities.
In this scheme, each node stores a set of pseudonyms of itself.
When two nodes, A and B, communicate, they first use pseudonyms to set up a shared session key in this way:
We think that this scheme is not strong enough to protect privacy in MANETs. The source node has to use real identity of destination when sending out a packet. The adversary can collect enough real identities and then try to match them to anonymous identities and link-ids with assistance of traffic analysis on payload.
Wednesday, January 16, 2019Wednesday, January 16, 2019
Amar B. Patel , Shushan Zhao

7. Amar B. Patel , Shushan Zhao
Proposed solution
We propose a solution to conceal real identities end to end in communication.
We propose a MANET system that takes into consideration the privacy of the identity, location, and moving track of a node.
We propose to use cluster-based structure to achieve a scalable privacy-protecting MANET system. Basically the system is divided into multiple clusters according to geographical or administrative relationships.
Figure 1. The structure of a Cluster-based MANET.
Wednesday, January 16, 2019Wednesday, January 16, 2019
Amar B. Patel , Shushan Zhao

8. A Scheme to Implement The System
Anonymous Identities and Communication inside a Cluster
Design a set of anonymous identities and distribute them among the cluster members. Since the membership of a cluster is rather stable, we have time to distribute the anonymous identities off-line and maybe update them periodically
E.g. A Pseudonym Hash-map Table
Wednesday, January 16, 2019Wednesday, January 16, 2019
Amar B. Patel , Shushan Zhao

9. A Scheme to Implement The System
Anonymous Identities and Communication between Clusterheads
Since clusters do not communicate regularly, and they need to communicate only in an ad hoc way, we cannot expect them to share the anonymous identity table in advance
Minimum data exchange and hide real identities on the fly
ElGamal encryption scheme
Determine and distribute <G, q, g> and a one-time key k
Identity Secret Key: k
Encrypted identities:
h= r: random
Identity Public Key:
Wednesday, January 16, 2019Wednesday, January 16, 2019
Amar B. Patel , Shushan Zhao

10. A Scheme to Implement The System
Anonymous Identities and Communication across Clusters
Encapsulated packets are used in case of forwarded packets from a non-head node inside one cluster to another non-head node inside another cluster.
The inner packet contains the real identity of a non-head node in the destination cluster.
Destination clusterhead decrypts and translates the real identity into intra-cluster anonymous identity before forwarding the packet to destination node.
Anonymous
ID of Destination
Clusterhead ID
Public
Key
Real ID of Destination Node
Message for Destination Node
Wednesday, January 16, 2019Wednesday, January 16, 2019
Amar B. Patel , Shushan Zhao

11. Improvement and Discussion
Our scheme is only a proof-of-concept system. Much room is left for improvement.
To improve the integrity of identities used in inter-cluster communications, we can use idea of [4] which is proposed originally for untraceable RFID tags.
In their scheme, the identity is accompanied by a certificate.
The certificate and the identity are bound together cryptographically. The identity cannot be forged unless the
adversary can also forge a certificate.
Wednesday, January 16, 2019Wednesday, January 16, 2019
Amar B. Patel , Shushan Zhao

12. Improvement and Discussion
A CA private-public key pair: (S, T)
A key generation pair:
Certificate of a Node:
Wednesday, January 16, 2019Wednesday, January 16, 2019
Amar B. Patel , Shushan Zhao

13. Amar B. Patel , Shushan Zhao
CONCLUSIONS
In this paper, we analyze the privacy issues that threat the MANETs
Particularly, to counter the identity exposure and traceability problems existing in MANETs, we propose a system architecture and implementation mechani-sms to protect this kind of privacy.
The system architecture is scalable and implemen-tation technologies are feasible.
Besides applicability to MANETs, the scheme can also be applied to wired networks that have concerns of privacy threats.
Wednesday, January 16, 2019Wednesday, January 16, 2019
Amar B. Patel , Shushan Zhao

14. Amar B. Patel , Shushan Zhao
REFERENCES
[1] Yanchao Zhang; Wei Liu; Wenjing Lou;
Anonymous communications in mobile ad hoc networks
INFOCOM th Annual Joint Conference of the IEEE Computer and
Communications Societies. Proceedings IEEE
Volume 3, March 2005 Page(s): vol. 3
[2] Jacobsson, M.; Niemegeers, I.; Privacy and Anonymity in Personal Networks
Pervasive Computing and Communications Workshops, PerCom 2005
Workshops. Third IEEE International Conference on 8-12 March 2005
Page(s):
[3] F. D¨otzer, “Privacy issues in vehicular ad hoc networks,” in Proc. of the
Workshop on Privacy Enhancing Technologies (PET), 2005.
[4] Giuseppe Ateniese, Jan Camenisch, Breno de Medeiros Untraceable RFID
Tags via Insubvertible Encryption Proceedings of the 12th ACM conference on
Computer and communications security CCS '05 November 2005, ACM Press
Wednesday, January 16, 2019Wednesday, January 16, 2019
Amar B. Patel , Shushan Zhao

15. Amar B. Patel , Shushan Zhao
Thanks
QUESTIONS?
Wednesday, January 16, 2019Wednesday, January 16, 2019
Amar B. Patel , Shushan Zhao