Transcript PPT - NetLab@SYSU

Privacy-Preserving Multi-keyword
Ranked Search
over Encrypted Cloud Data
Presenter ：刘 燕
 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
document
• 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 Scheme
1) 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. Efficiency
1) 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!
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