1. EPPA: An Efficient and Privacy-Preserving Aggregation Scheme for Secure Smart Grid Communications Rongxing Lu, Xiaohui Liang, Xu Li, Xiaodong Lin, Xuemin (Sherman) Shen IEEE TRANSACTIONS ON PARALLEL AND DISTRIBUTED SYSTEMS VOL. 23, NO. 9, SEPTEMBER 2012 Presenter : 周新偉 Date:2014/10/27 1

2. Outline Intorduction Systrm Model,Security Requirement And Design Model Preliminaries EPPA Schmem Security Analysis Performance Conclusions 2

3. Outline Intorduction Systrm Model,Security Requirement And Design Model Preliminaries EPPA Schmem Security Analysis Performance Conclusions 3

4. Intorduction 4

5. Outline Intorduction Systrm Model,Security Requirement And Design Model Preliminaries EPPA Schmem Security Analysis Performance Conclusions 5

6. System Model 6

7. Security Requirements Confidentiality Authentication and Data Integrity 7

8. Design Goal The secure requirement should be guaranteed in the proposed scheme The communication effectiveness should be achieved in the proposed scheme 8

9. Outline Intorduction Systrm Model,Security Requirement And Design Model Preliminaries EPPA Schmem Security Analysis Performance Conclusions 9

10. Preliminaries 10

11. Preliminaries----- Paillier Cryptosystem(1/3) Key Generation security parameter κ 1 large prime p 1, q 1 | p 1 |=|q 1 |=|κ 1 | RSA modulus : n=p 1 * q 1 λ=lcm(p 1 -1, q 1 -1 ) L(u)=(u-1)/n μ=(L(g λ modn 2 )) -1 mod n Public key pk = (n,g) Privite key sk = (λ, μ) 11

12. Preliminaries----- Paillier Crypyosystem(2/3) 12

13. Preliminaries----- Paillier Crypyosystem(3/3) 13

14. Outline Introduction System Model, Security Requirement And Design Model Preliminaries EPPA Scheme Security Analysis Performance Conclusions 14

15. EPPA Scheme--- System Initialization(1/3) 15

16. EPPA Scheme--- System Initialization(2/3) 16

17. EPPA Scheme--- System Initialization(3/3) 17

18. EPPA Scheme--- User Report Generation 18

19. EPPA Scheme--- Privacy-Preserving Report Aggregation 19

20. EPPA Scheme--- Privacy-Preserving Report Aggregation After validity checking, the following steps for privacy-preserving report aggregation : 20

21. EPPA Scheme--- Secure Report Reading And Response(1/6) 21

22. EPPA Scheme--- Secure Report Reading And Response(2/6) Taking And the report C=g M R n mod n 2 is still ciphertext for Paillier Cryptosystem OA use master key to recover M 22

23. EPPA Scheme--- Secure Report Reading And Response(3/6) By invoking algorithm 1,OA can recover and store the aggregated data 23

24. EPPA Scheme--- Secure Report Reading And Response(4/6) Correctness of algorithm 1,assume X l =M Since any type of data is less than d, 24

25. EPPA Scheme--- Secure Report Reading And Response(5/6) 25

26. EPPA Scheme--- Secure Report Reading And Response(6/6) 26

27. Outline Intorduction Systrm Model,Security Requirement And Design Model Preliminaries EPPA Schmem Security Analysis Performance Conclusions 27

28. Security Analysis(1/2) 28

29. Security Analysis(2/2) 29

30. Outline Intorduction Systrm Model,Security Requirement And Design Model Preliminaries EPPA Schmem Security Analysis Performance Conclusions 30

31. Performance(1/3) 31

32. Performance(1/3) 32

33. Performance(2/3) 33

34. Performance(3/3) 34

35. Outline Intorduction Systrm Model,Security Requirement And Design Model Preliminaries EPPA Schmem Security Analysis Performance Conclusions 35

36. Conclusions In this paper, we have proposed an efficient and privacypreserving aggregation scheme for secure smart grid communications. It realizes a multidimensional data aggregation approach based on the homomorphic Paillier cryptosystem. Compared with the traditional one-dimensional data aggregation methods, EPPA can significantly reduce computational cost and significantly improve communication efficiency, satisfying the real-time high-frequency data collection requirements in smart grid communications. We have also provided security analysis to demonstrate its security strength and privacy- preserving ability, and performance analysis to show the efficiency improvement. For the future work, we will study the possible behavior by internal attackers and extend the EPPA scheme to effectively resist such attacks. 36

37. 心得 37

38. 38 Thanks for your listening