privacy-preserving multi-keyword ranked search over encrypted cloud data presenter ： 刘 燕

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!