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

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

3. inner product similarity
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. Preliminary on Coordinate Matching
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]= = = =
S[j]= =
= =

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!