Smartening the Environment using Wireless Sensor Networks in a Developing Country

1. Smartening the Environment using Wireless Sensor Networks in a Developing Country SECRET: A Secure and Efficient Certificate Revocation Scheme for Mobile Ad Hoc Networks Dieynaba Mall1, Karim Konaté1, and Al-Sakib Khan Pathan2 1Department of Mathematics and Computer Science, UniversitéCheikh Anta Diop de Dakar, Dakar, Senegal 2Department of Computer Science, International Islamic University Malaysia, Kuala Lumpur, Malaysia Presented By: Al-SakibKhan Pathan

2. Outline of This Presentation • Introduction • Motivation and Objectives • The proposed scheme • Analysis – security and performance • Future research directions ISBAST 2014, 26-27 August 2014, KL, Malaysia

3. Introduction • In Mobile Ad hoc Networks (MANETs), the nodes maintain the network by communicating among themselves without any particular centralized entity. • Due to the nature of wireless communication, MANETs are more vulnerable. • Key management is used for secure communication • Key distribution is mainly discussed • Key revocation is also critical ISBAST 2014, 26-27 August 2014, KL, Malaysia

4. Motivation Behind This Work • Most of the proposed certificate revocation schemes in MANET present many insufficiencies: • Vulnerable to various types of attacks and do not guarantee efficient resource utilization. • Only digital signature-based schemes addressed resource-efficiency. However, the cost associated with using such operations is still substantially higher than that of symmetric cryptographic operations. • Signature-based broadcast authentication protocols are vulnerable to DoS (Denial of Service) attacks. ISBAST 2014, 26-27 August 2014, KL, Malaysia

5. Objective and Overview • We propose an enhanced and efficient certificate/key revocation scheme for Mobile Ad hoc Networks (MANETs). • Specific contribution: Our key revocation scheme is based on the scheme presented in the following work (identity based approach): • K. Hoeper and G. Gong, Monitoring-Based Key Revocation Schemes for Mobile Ad Hoc Networks: Design and Security Analysis. Technical Report 9 2009-15, Centre for Applied Cryptographic Research, March 2009. ISBAST 2014, 26-27 August 2014, KL, Malaysia

6. Objective and Overview • Identity-based cryptography is a type of public-key cryptography in which a publicly known string representing an individual or organization is used as a public key. The public string could include an email address, domain name, or a physical IP address. • Two main issues are addressed in our work: • Vulnerability against various attacks • Resource consumption / Resource-efficiency ISBAST 2014, 26-27 August 2014, KL, Malaysia

7. Building Blocks of Our Scheme • We adapt and modify the work of Hoeper and Gong. • Employ the HEAP protocol as the underlying broadcast authentication scheme: • R. Akbani, T. Korkmaz, and G. V. S. Raju., “HEAP: hop-by-hop efficient authentication protocol for Mobile Ad-hoc Networks,” Proc. of the 2007 spring simulation multiconference - Volume 1 (SpringSim '07), Vol. 1. Society for Computer Simulation International, 2007, San Diego, CA, USA, pp. 157-165. ISBAST 2014, 26-27 August 2014, KL, Malaysia

8. Security Assumptions • We assume a PKI (Public Key Infrastructure)-based system with an external trusted certificate authority, CA (Certification Authority). • We consider that each node can communicate with this trusted CA before joining the network and can obtain a unique public key certificate signed by the CA as well as the authentic public key of the CA. • A public key certificate (also known as a digital certificate or identity certificate) is an electronic document used to prove ownership of a public key. ISBAST 2014, 26-27 August 2014, KL, Malaysia

9. Security Assumptions (Cntd.) • All direct communication links between nodes are bidirectional and each node has an implemented monitoring scheme. • Each node knows its one-hop neighbors - this is necessary to assure a complete distribution of shared keys. ISBAST 2014, 26-27 August 2014, KL, Malaysia

10. Proposed Scheme • Our proposal comprises of three algorithms • Before presenting the algorithms, let us know, • All the mathematical notations and their meanings • Certificate Revocation Lists (CRLs) ISBAST 2014, 26-27 August 2014, KL, Malaysia

11. Mathematical Notations TABLE 1. LIST OF NOTATIONS FOR CERTIFICATE REVOCATION SCHEME ISBAST 2014, 26-27 August 2014, KL, Malaysia

12. Certificate Revocation Lists • Each node icreates a certificate revocation list CRLi for any of its known nodes j such that j∈Ni. • This list can be represented by a matrix with dimensions (Ωi,Ωi+3) as shown below: ISBAST 2014, 26-27 August 2014, KL, Malaysia

13. Our Revocation Scheme • We use: • Certificate revocation lists instead of key revocation lists, and • The HEAP protocol as broadcast authentication scheme. Hence, shared keys are used to secure accusation messages. The combination gives significant advantage over the previous approach. ISBAST 2014, 26-27 August 2014, KL, Malaysia

14. Our Revocation Scheme (Ctnd.) • Algorithm 1: Neighborhood Watch • In this algorithm, each node i monitors its one-hop neighbors. Whenever it observes a suspicious neighborj∈Ni,1, it sets and creates a neighborhood watch message nwi with: MAC - Message Authentication Code ISBAST 2014, 26-27 August 2014, KL, Malaysia

15. Our Revocation Scheme (Ctnd.) • where, , containing ; • certi is the serial number of i’s certificate; • hopcountensures that the message reaches all nodes in m-hop distance. Initially, node i sets hopcount = m. • index is the index number related to this message and used to prevent replay attacks. • and are the different MACs computed each for a one-hop neighbor according to the New Step 2 in the paper. ISBAST 2014, 26-27 August 2014, KL, Malaysia

16. Our Revocation Scheme (Ctnd.) • Algorithm 2: Propagate • This algorithm is triggered by Algorithms 1 and 3. After creating an accusation message which can be neighborhood watch message nwi or update message umi, the nodes securely propagate accusations to their one-hop neighbors. ISBAST 2014, 26-27 August 2014, KL, Malaysia

17. Our Revocation Scheme (Ctnd.) • Algorithm 3: Update CRL • This algorithm describes how the node i updates its own revocation list CRLi according to the received accusation message. • Node i prepares an update message umi for all of its one-hop neighbors j∈Ni,1 with: where M contains the parameters as noted before. ISBAST 2014, 26-27 August 2014, KL, Malaysia

18. Security Analysis • The use of HEAP as authentication scheme provides a foundation. • With HEAP, our revocation scheme can authenticate every single packet in every single hop. Hence, it can combat • replay, impersonation, DoS, man-in-the-middle, wormhole attacks, etc. • In addition, HEAP offers some level of protection against insider attackers who try to forge packets and impersonate other insiders. ISBAST 2014, 26-27 August 2014, KL, Malaysia

19. Security Analysis (Ctnd.) • Our scheme defends against a wide range of insider attacks by using intelligent techniques, security, and system parameters (in Table 1). • Protection against: • Sybil attack • Dropping accusations • Attempt to modify accusations • Moving to a new neighborhood whenever accusation account approaches threshold • Collusion of nodes ISBAST 2014, 26-27 August 2014, KL, Malaysia

20. Performance Analysis TABLE 2 [16] K. Hoeper and G. Gong, Monitoring-Based Key Revocation Schemes for Mobile Ad Hoc Networks: Design and Security Analysis. Technical Report 9 2009-15, Centre for Applied Cryptographic Research, March 2009. ISBAST 2014, 26-27 August 2014, KL, Malaysia

21. Performance Analysis • With our approach, • the memory space required to store the required information slightly increases due to the storage of certificate of each one-hop neighbor. • the computational overhead generated by an accusation message in our solution remains the same as the one associated with the proposal in [16] ISBAST 2014, 26-27 August 2014, KL, Malaysia

22. Performance Analysis • With our approach, • to disseminate an accusation message to the one-hop neighborhood, a node i just needs to execute one broadcast. Thus, compared to the method in [16], our solution considerably reduces the communication overhead associated to the propagation of accusations. • Note that in [16], due to the use of pairwise pre-shared secret keys ki,j, to propagate an accusation, it is required to unicast the associated message to each one-hop neighbor. ISBAST 2014, 26-27 August 2014, KL, Malaysia

23. Final Words and Overall Gains • Security and performance analyses show that our approach ensures • good protection against a wide range of attacks launched by outsiders • Also, insider attacks in a cost-effective way since our scheme offers smaller overheads. • Future work is to investigate applicability of the scheme for other networks and possibly, to further reduce complexity. ISBAST 2014, 26-27 August 2014, KL, Malaysia

24. THANK YOU ISBAST 2014, 26-27 August 2014, KL, Malaysia

25. Questions and Answers Any query should be directed to sakib.pathan@gmail.com , sakib@iium.edu.my ??? For More Information: http://staff.iium.edu.my/sakib/ ISBAST 2014, 26-27 August 2014, KL, Malaysia