Privacy-Preserving Multi-keyword Ranked Search
over Encrypted Cloud Data
Presenter ：刘 燕
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INTRODUCTION PROBLEM FORMULATION FRAMEWORK AND PRIVACY
REQUIREMENTS FOR MRSE PRIVACY-PRESERVING AND EFFICIENT
MRSE PERFORMANCE ANALYSIS RELATED WORK CONCLUSION
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INTRODUCTION
• coordinate matching as many matches as possible
• inner product similarity the number of query keywords appearing in a doc
ument
• k-nearest neighbor technique
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PROBLEM FORMULATION
System Model
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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
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PROBLEM FORMULATION
Design Goals
Multi-keyword Ranked Search
Privacy-Preserving
Efficiency
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PROBLEM FORMULATION
Notations
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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
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FRAMEWORK AND PRIVACY REQUIREMENTS
MRSE Framework
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FRAMEWORK AND PRIVACY REQUIREMENTS
Privacy Requirements for MRSE Keyword Privacy
Trapdoor Privacy
Search Pattern
Access Pattern
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PRIVACY-PRESERVING AND EFFICIENT MRSE
A. MRSE I: Basic Scheme
1) Secure kNN Computation
[d+1]=
[d+1]= 1
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PRIVACY-PRESERVING AND EFFICIENT MRSE
S[j]=0 = =
+ =
S[j]=1 + =
= =
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PRIVACY-PRESERVING AND EFFICIENT MRSE
2) MRSE I Scheme:
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PRIVACY-PRESERVING AND EFFICIENT MRSE
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PRIVACY-PRESERVING AND EFFICIENT MRSE
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PRIVACY-PRESERVING AND EFFICIENT MRSE
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PRIVACY-PRESERVING AND EFFICIENT MRSE
MRSE II: Privacy-Preserving Scheme 1) Min/Max Score Analysis Attack:
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PRIVACY-PRESERVING AND EFFICIENT MRSE
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PRIVACY-PRESERVING AND EFFICIENT MRSE
2) MRSE II Scheme:
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PRIVACY-PRESERVING AND EFFICIENT MRSE
MRSE III: Privacy-Preserving Scheme1) Scale Analysis Attack:
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PRIVACY-PRESERVING AND EFFICIENT MRSE
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PRIVACY-PRESERVING AND EFFICIENT MRSE
2) MRSE III Scheme:
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PERFORMANCE ANALYSIS
A. Precision and Privacy
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PERFORMANCE ANALYSIS
B. Efficiency1) Index Construction:
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PERFORMANCE ANALYSIS
2) Trapdoor Generation:
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PERFORMANCE ANALYSIS
3) Query:
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RELATED WORK
• Single Keyword Searchable Encryption
• Boolean Keyword Searchable Encryption
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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
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The End
Thank You!
