Privacy-Preserving Multi-keyword Ranked Search over Encrypted Cloud Data Presenter ： 刘 燕

1. Privacy-Preserving Multi-keyword Ranked Searchover Encrypted Cloud DataPresenter ：刘 燕

2. INTRODUCTION • PROBLEM FORMULATION • FRAMEWORK AND PRIVACY REQUIREMENTS FOR MRSE • PRIVACY-PRESERVING AND EFFICIENT MRSE • PERFORMANCE ANALYSIS • RELATED WORK • CONCLUSION

3. INTRODUCTION • coordinate matching as many matches as possible • inner product similarity the number of query keywords appearing in a document • k-nearest neighbor technique

4. PROBLEM FORMULATION System Model

5. PROBLEM FORMULATION Threat Model • Known Ciphertext Model only know encrypted dataset C and searchable index I • Known Background Model know encrypted dataset C , searchable index I and some backgrounds on the dataset

6. PROBLEM FORMULATION Design Goals • Multi-keyword Ranked Search • Privacy-Preserving • Efficiency

7. PROBLEM FORMULATION Notations

8. PROBLEM FORMULATION Preliminary on Coordinate Matching • a hybrid of conjunctive search and disjunctive search • uses the number of query keywords appearing in the document to quantify the similarity of that document to the query

9. FRAMEWORK AND PRIVACY REQUIREMENTS MRSE Framework

10. FRAMEWORK AND PRIVACY REQUIREMENTS Privacy Requirements for MRSE • Keyword Privacy • Trapdoor Privacy • Search Pattern • Access Pattern

11. PRIVACY-PRESERVING AND EFFICIENT MRSE • MRSE I: Basic Scheme • Secure kNN Computation [d+1]= [d+1]= 1

12. PRIVACY-PRESERVING AND EFFICIENT MRSE S[j]=0 = = + = S[j]=1 + = = =

13. PRIVACY-PRESERVING AND EFFICIENT MRSE 2) MRSE I Scheme:

14. PRIVACY-PRESERVING AND EFFICIENT MRSE

15. PRIVACY-PRESERVING AND EFFICIENT MRSE

16. PRIVACY-PRESERVING AND EFFICIENT MRSE

17. PRIVACY-PRESERVING AND EFFICIENT MRSE MRSE II: Privacy-Preserving Scheme 1) Min/Max Score Analysis Attack:

18. PRIVACY-PRESERVING AND EFFICIENT MRSE

19. PRIVACY-PRESERVING AND EFFICIENT MRSE 2) MRSE II Scheme:

20. PRIVACY-PRESERVING AND EFFICIENT MRSE MRSE III: Privacy-Preserving Scheme 1) Scale Analysis Attack:

21. PRIVACY-PRESERVING AND EFFICIENT MRSE

22. PRIVACY-PRESERVING AND EFFICIENT MRSE 2) MRSE III Scheme:

23. PERFORMANCE ANALYSIS A. Precision and Privacy

24. PERFORMANCE ANALYSIS B. Efficiency 1) Index Construction:

25. PERFORMANCE ANALYSIS 2) Trapdoor Generation:

26. PERFORMANCE ANALYSIS 3) Query:

27. RELATED WORK • Single Keyword Searchable Encryption • Boolean Keyword Searchable Encryption

28. CONCLUSION • Coordinate Matching as many matches as possible • Inner Product Similarity • Basic MRSE Scheme • Privacy-Preserving Scheme in Known Ciphertext Model • Privacy-Preserving Scheme in Known Background Mode

29. Thank You!