1. Source: KSII Transactions On Internet And Information Systems Vol. 3, No. 2, April 2009 Authors: Abedelaziz Mohaisen, DaeHun Nyang, YoungJae Maeng, KyungHee Lee, Dowon Hong Presenter: Hsing-Lei Wang Date: 2010/11/26 1

2. Outline Introduction Related Works The Proposed Scheme Grid-Based Key Pre-Distribution in WSN (3D) Analysis Conclusions Comment 2

3. Introduction 3 A Grid-Based Key Pre-Distribution Scheme (3D)  Goal: Improve the connectivity and resiliency

4. Related Works (Blundo et al. scheme, 1993) 4 Polynomial-Based Key Pre-Distribution Scheme

5. Grid-Based Key Pre-Distribution Scheme (1/2) Related Works (Liu et al. scheme, 2003) 5

6. 6 Grid-Based Key Pre-Distribution Scheme (2/2) Related Works (Liu et al. scheme, 2003)

7. The Proposed Scheme 7 3D Grid-Based Key Pre-Distribution Scheme (1/11)

8. 8 The Proposed Scheme 3D Grid-Based Key Pre-Distribution Scheme (2/11)

9. 9 The Proposed Scheme 3D Grid-Based Key Pre-Distribution Scheme (3/11)

10. 10 The Proposed Scheme 3D Grid-Based Key Pre-Distribution Scheme (4/11)

11. 11 The Proposed Scheme 3D Grid-Based Key Pre-Distribution Scheme (5/11)

12. 12 The Proposed Scheme 3D Grid-Based Key Pre-Distribution Scheme (6/11)

13. 13 The Proposed Scheme 3D Grid-Based Key Pre-Distribution Scheme (7/11)

14. 14 The Proposed Scheme 3D Grid-Based Key Pre-Distribution Scheme (8/11)

15. 15 The Proposed Scheme 3D Grid-Based Key Pre-Distribution Scheme (9/11)

16. 16 The Proposed Scheme 3D Grid-Based Key Pre-Distribution Scheme (10/11)

17. 17 The Proposed Scheme 3D Grid-Based Key Pre-Distribution Scheme (11/11)

18. Analysis Connectivity 18

19. Analysis Resiliency 19

20. Comparison 20

21. Conclusions Original contribution: Introduce a grid-based key pre-distribution scheme that utilizes the notion of plats on grid Plat-based polynomial assignment The advantages of the proposed scheme Guarantees higher connectivity More possible intermediate nodes, better resiliency 21

22. Comment In the Key Establishment phase, the authors do not describe how the sensor node find the intermediate node for indirect key establishment. 22