Table of contents : Contents Acronyms Part I Privacy Preserving Queries 1 Range Queries over Encrypted Data 1.1 Introduction 1.1.1 Background and Motivation 1.1.2 Threat Model 1.1.3 Security Model 1.1.4 Summary and Limitation of Prior Art 1.1.5 Proposed Approach 1.1.6 Technical Challenges and Solutions 1.1.7 Key Contributions 1.2 Related Work 1.3 PBtree Construction 1.3.1 Prefix Encoding 1.3.2 Tree Construction 1.3.3 Node Randomization Using Bloom Filters 1.3.4 Trapdoor Computation 1.3.5 Query Processing 1.3.6 False Positive Analysis 1.4 PBtree Search Optimization 1.4.1 Traversal Width Optimization 1.4.2 Traversal Depth Optimization 1.5 PBtree Update 1.5.1 PBtree Insertion Algorithm 1.5.2 PBtree Modification Algorithm 1.5.3 PBtree Deletion Algorithm 1.6 Security Analysis 1.6.1 Security Model 1.6.2 Security Proof 1.7 Experimental Evaluation 1.7.1 Experimental Methodology 1.7.1.1 Data Sets 1.7.1.2 PBtree Types 1.7.1.3 Query Types 1.7.1.4 Implementation Details 1.7.2 Evaluation of PBtree Construction 1.7.3 Query Evaluation Performance 1.7.3.1 Prefix Query Evaluation 1.7.3.2 Range Query Evaluation 1.7.4 Experimental Results on Updating 1.7.4.1 Average Time of Updating 1.7.4.2 Communication Cost of Updating 1.8 Conclusions References 2 Fast and Scalable Range and Keyword Query Processing Over Encrypted Data with Provable Adaptive Security 2.1 Introduction 2.1.1 Motivation and Problem Statement 2.1.2 Threat Model 2.1.3 Security Model 2.1.4 Limitation of Prior Art 2.1.5 Proposed Approach 2.1.6 Novelty and Advantages Over Prior Art 2.2 Related Work 2.3 Basic IBtree Algorithms 2.3.1 Index Element Encoding 2.3.2 IBF Construction 2.3.3 IBtree Construction 2.3.4 Trapdoor Computation 2.3.5 Query Processing 2.4 Optimized IBtree Algorithms 2.4.1 IBtree Traversal Width Minimization 2.4.2 IBtree Traversal Depth Minimization 2.4.3 IBtree Compression 2.5 Security Analysis 2.6 Experimental Evaluation 2.6.1 Experimental Methodology 2.6.2 Index Size 2.6.3 Index Construction Time 2.6.4 Query Processing Time 2.6.5 Compared with PBtree and KRB 2.7 Conclusions References 3 Nearest Neighbor Queries over Encrypted Data 3.1 Introduction 3.2 Insecurity of ASPE 3.2.1 ASPE I and II 3.2.2 Attack Method 3.2.3 Experimental Results 3.3 Hardness Analysis 3.4 Conclusions References 4 K-Nearest Neighbor Queries Over Encrypted Data 4.1 Introduction 4.1.1 Motivations 4.1.2 Problem Formulation 4.1.3 Service Model and Design Goals 4.1.4 Comparison with Prior Arts 4.1.5 Technical Challenges and Proposed Solutions 4.1.6 SecEQP Scheme Overview 4.1.7 Main Contributions 4.2 Space Encoding 4.2.1 Projection Function Introduction 4.2.2 Space Encoding via a Single Primitive Projection Function 4.2.3 Projection Function Composition Introduction 4.2.4 Space Encoding via Projection Function Composition 4.3 kNN Protocol for Plaintext Domain 4.3.1 kNN Protocol Design 4.3.2 Analysis of kNN Protocol Parameters 4.4 Transforming kNN to Secure kNN 4.4.1 Prefix-Free Encoding 4.4.2 Operation Transformation 4.4.3 Indistinguishable Bloom Filter Tree Based Secure Index 4.4.4 SkNN Protocol (SecEQP) Design 4.4.5 Security Analysis 4.5 Performance Evaluation 4.5.1 Parameters Settings 4.5.2 Datasets, Metrics, and Implementation 4.5.3 Experiment Results 4.5.4 Improve Result Accuracy 4.6 Related Work 4.7 Conclusions References 5 Top-k Queries for Two-Tiered Sensor Networks 5.1 Introduction 5.1.1 Motivation 5.1.2 Problem Statement 5.1.3 Adversary and Security Model 5.1.4 Limitations of Prior Art 5.1.5 Technical Challenges and Proposed Approach 5.1.6 Key Contributions 5.2 Related Work 5.3 System Model and Assumptions 5.4 Sensor Data Pre-Processing: Mapping and Partitioning 5.4.1 Approximating Uniform Distribution 5.4.2 Data Partitioning for Integrity Verification 5.4.3 Embedding Intervals with Data 5.4.4 Index Selection 5.5 Privacy Preserving Index Generation 5.5.1 Prefix Encoding and Bloom Filter Indexing 5.5.2 Randomizing Bloom Filter Indexes 5.6 Trapdoor Computation and Query Processing 5.6.1 Top-k to Top-Range Query 5.6.2 Trapdoor Computation 5.6.3 Query Execution 5.6.4 Integrity Verification for Query Results 5.6.5 False Positive Rate Analysis 5.7 Security Analysis 5.8 Performance Evaluation 5.8.1 Experimental Setup 5.8.2 Summary for Experimental Results 5.8.3 Comparison with Prior Art 5.9 Conclusions References Part II Privacy Preserving Computation 6 Collaborative Enforcement of Firewall Policies in Virtual Private Networks 6.1 Introduction 6.1.1 Background and Motivation 6.1.2 Technical Challenges 6.1.3 Limitations of Prior Art 6.1.4 Our Solution 6.1.5 Key Contributions 6.2 Threat Model 6.3 Background 6.4 Oblivious Comparison 6.5 Bootstrapping Protocol 6.5.1 FDD Construction 6.5.2 Range Conversion 6.5.3 Prefix Numericalization 6.5.4 Applying XOR by MSU 6.5.5 Applying XOR and HMAC by IBM 6.6 Filtering Protocol 6.6.1 Address Translation 6.6.2 Prefix Membership Verification 6.6.3 Packet Preprocessing by IBM 6.6.4 Packet Preprocessing by The Third Party 6.6.5 Packet Processing by MSU 6.7 VGuard for Deep Packet Inspection 6.7.1 The Bootstrapping Protocol 6.7.2 The Filtering Protocol 6.8 Discussion 6.8.1 Firewall Updates 6.8.2 Decision Caching 6.8.3 Decision Obfuscation vs. Decision Encryption 6.8.4 Special Treatment of IP Addresses 6.8.5 Securing Keys of MSU 6.8.6 Stateful Firewalls 6.8.7 Statistical Analysis Attack and Countermeasures 6.8.8 Hash Collision 6.9 Related Work 6.9.1 Secure Function Evaluation 6.9.2 CDCF Framework 6.9.3 Secure Queries 6.10 Experimental Results 6.10.1 Efficiency on Real-Life Firewall Policies 6.10.2 Efficiency on Synthetic Firewall Policies 6.11 Concluding Remarks References 7 Privacy Preserving Quantification of Cross-Domain Network Reachability 7.1 Introduction 7.1.1 Background and Motivation 7.1.2 Limitation of Prior Art 7.1.3 Cross-Domain Quantification of Reachability 7.1.4 Technical Challenges 7.1.5 Our Approach 7.1.6 Summary of Experimental Results 7.1.7 Key Contributions 7.2 Related Work 7.2.1 Network Reachability 7.2.2 Privacy Preserving Set Operation 7.2.3 Privacy Preserving Collaborative Firewall Enforcement in VPN 7.3 Problem Statement and Threat Model 7.3.1 Access Control Lists (ACLs) 7.3.2 Problem Statement 7.3.3 Threat Model 7.4 Privacy-Preserving Quantification of Network Reachability 7.4.1 Privacy-Preserving Range Intersection 7.4.1.1 [Pi]: Range Transformation 7.4.1.2 [Pi]: Range to Prefix Set Conversion 7.4.1.3 [Pj]: Prefix Family Generation 7.4.1.4 [Pi, Pj]: Prefix Numericalization 7.4.1.5 [Pi, Pj]: Private Set Intersection 7.4.2 ACL Preprocessing 7.4.3 ACL Encoding and Encryption 7.4.3.1 Encoding and Encryption of ACL Aj (1≤j ≤n-1) 7.4.3.2 Encoding and Encryption of ACL An 7.4.4 ACL Comparison 7.5 Incremental Updates of ACLs 7.5.1 Addition of Rules with Accept Decision 7.5.2 Addition of Rules with Discard Decision 7.5.3 Addition of New Routers 7.6 Stateful Firewalls 7.7 Security and Complexity Analysis 7.7.1 Security Analysis 7.7.2 Complexity Analysis 7.8 Protocol Optimization 7.9 Experimental Results 7.9.1 Efficiency on Real ACLs 7.9.2 Efficiency on Synthetic ACLs 7.9.3 Efficiency of Incremental Updates of ACLs 7.10 Conclusions References 8 Cross-Domain Privacy-Preserving Cooperative Firewall Optimization 8.1 Introduction 8.1.1 Background and Motivation 8.1.2 Limitation of Prior Work 8.1.3 Cross-Domain Inter-Firewall Optimization 8.1.4 Technical Challenges and Our Approach 8.1.5 Key Contributions 8.2 Related Work 8.2.1 Firewall Redundancy Removal 8.2.2 Collaborative Firewall Enforcement in VPN 8.3 System and Threat Models 8.3.1 System Model 8.3.2 Threat Model 8.4 Privacy-Preserving Inter-Firewall Redundancy Removal 8.4.1 Privacy-Preserving Range Comparison 8.4.2 Processing Firewall FW1 8.4.3 Processing Firewall FW2 8.4.4 Single-Rule Coverage Redundancy Detection 8.4.5 Multi-Rule Coverage Redundancy Detection 8.4.6 Identification and Removal of Redundant Rules 8.5 Firewall Update After Optimization 8.6 Security and Complexity Analysis 8.6.1 Security Analysis 8.6.2 Complexity Analysis 8.7 Experimental Results 8.7.1 Evaluation Setup 8.7.2 Methodology 8.7.3 Effectiveness and Efficiency on Real Policies 8.7.4 Efficiency on Synthetic Policies 8.8 Conclusions and Future Work References 9 Privacy Preserving String Matching for Cloud Computing 9.1 Introduction 9.1.1 Motivation 9.1.2 Problem Statement 9.1.3 Adversary and Security Model 9.1.4 Limitation of Prior Art 9.1.5 Proposed Approach 9.1.6 Technical Challenges and Solutions 9.1.7 Key Contributions 9.2 Related Work 9.3 Pattern Aware Secure Search Tree 9.3.1 String Pattern Matching 9.3.2 PASStree Structure 9.3.3 Preserving Privacy of Bloom Filters 9.3.4 Query Trapdoor Generation and Processing 9.4 PASStree+ 9.4.1 Challenge in Search Optimization 9.4.2 Optimizing PASStree 9.5 Ranking Search Results 9.5.1 Recording Matching Positions 9.5.2 Ranking Algorithm 9.6 Security Analysis 9.6.1 Security Model 9.6.2 Security Proof 9.7 Performance Evaluation 9.7.1 Experimental Methodology 9.7.1.1 Data Sets 9.7.1.2 Implementation Details 9.7.1.3 Query Types 9.7.2 PASStree Construction and Size 9.7.3 Query Processing Speed and Accuracy 9.7.4 Ranking Precision 9.8 Conclusion and Future Work References 10 Privacy Preserving Information Hub Identification in Social Networks 10.1 Introduction 10.1.1 Background and Motivation 10.1.2 Limitations of Prior Art 10.1.3 Proposed Solution 10.1.4 Results and Findings 10.1.5 Key Contributions 10.2 Related Work 10.3 Proposed Solution 10.3.1 Eigenvector Centrality 10.3.2 Motivation for Principal Component Centrality 10.3.3 Definition of PCC 10.3.4 Generalized PCC 10.3.5 Selection of Number of Eigenvectors 10.3.6 Decentralized Eigendecomposition Algorithm 10.4 Performance Evaluation 10.4.1 Data Sets 10.4.1.1 Facebook A and Facebook B 10.4.1.2 Twitter 10.4.2 Selection of PCC Parameter 10.4.3 Comparison with Ground Truth 10.4.3.1 Verification of Optimal PCC Parameter 10.4.3.2 Accuracy of PCC in Predicting Top-2000 Users 10.4.3.3 Accuracy of PCC in Predicting Top-k Users 10.4.3.4 Accuracy of PCC in Rank Prediction 10.5 Conclusions References Part III Differential Privacy 11 Publishing Social Network Data with Privacy Guarantees 11.1 Introduction 11.1.1 Background and Motivation 11.1.2 Problem Statement 11.1.3 Limitations of Prior Art 11.1.4 Proposed Approach 11.1.5 Technical Challenges 11.1.6 Key Contributions 11.2 Related Work 11.2.1 Differential Privacy 11.2.2 Differential Privacy in Data Publishing 11.3 Random Matrix Approach 11.3.1 Theoretical Guarantee on Differential Privacy 11.3.2 Theoretical Guarantee on Eigenvector Approximation 11.4 Experimental Results 11.4.1 Dataset 11.4.2 Node Clustering 11.4.3 Node Ranking 11.5 Utility Comparison 11.6 Conclusions References 12 Predictable Privacy-Preserving Mobile Crowd Sensing 12.1 Introduction 12.2 Related Work 12.3 Privacy of MCS 12.3.1 Threat Model 12.3.2 Data Reconstruction Attack 12.4 Differentially Private Mechanisms for Privacy-Preserving MCS 12.4.1 Models and Definitions 12.4.1.1 Overview of the System Model 12.4.1.2 Differential Privacy 12.4.1.3 Sensitivity 12.4.1.4 Laplacian Random Variables and Vectors 12.4.2 The Basic Laplacian Mechanism 12.4.3 The Salus Algorithm 12.4.3.1 Enhanced Feature #1: Value Protection 12.4.3.2 Enhanced Feature #2: Trend Protection 12.4.3.3 The Final Salus Algorithm 12.4.3.4 Privacy Analysis of Salus Algorithm 12.5 Role User: The Privacy Quantification 12.5.1 Data Reconstruction Error: A Quantitative Analysis 12.5.2 Data Reconstruction Error: A Lower Bound 12.6 Role Application Publisher: The Utility Prediction 12.6.1 Average (AVG) 12.6.2 Histogram (HIST) 12.6.3 Classifiers (CLS) 12.7 The P3 Framework for Predictable Privacy-Preserving MCS 12.8 Performance Evaluation 12.8.1 Privacy Protection 12.8.2 System Overhead 12.8.3 Case Studies 12.8.3.1 Community Health Survey 12.8.3.2 Collaborative Emotion Classification 12.9 Conclusions References 13 Differentially Private and Budget Limited Bandit Learning over Matroids 13.1 Introduction 13.1.1 Limitations of Prior Art 13.1.2 Proposed Approach 13.1.3 Advantages over Prior Art 13.2 Related Work 13.2.1 MAB Algorithms Without Budgets 13.2.2 MAB Algorithms with Budgets 13.2.3 Privacy-Aware Online Learning 13.3 Problem Statement 13.3.1 Matroids 13.3.2 DP-Aware BMAB Over Matroids 13.3.3 An Example in Crowdsourcing 13.4 Bounding the Optimal Policy 13.5 Algorithm Design 13.5.1 Ensuring Differential Privacy 13.5.2 The OPBM Algorithm 13.6 Regret Analysis 13.7 Performance Evaluation 13.7.1 Experimental Setup 13.7.2 Metrics 13.7.3 Regret Performance 13.7.4 Time Efficiency 13.8 Conclusion Appendix: Missing Definitions, Lemmas and Proofs Proof of Lemma 13.1 Proof of Theorem 13.1 Proof of Lemma 13.6 Proof of Lemma 13.8 Proof of Lemma 13.9 Proof of Lemma 13.10 Proof of Lemma 13.11 Proof of Theorem 13.4 Proof of Theorem 13.5 References Part IV Breaking Privacy 14 Breaching Privacy in Encrypted Instant Messaging Networks 14.1 Introduction 14.1.1 Chapter Organization 14.2 Related Work 14.2.1 Mix Network De-anonymization 14.2.2 Social Network De-anonymization 14.3 Problem Description and Attack Scenarios 14.3.1 IM Service Architecture 14.3.2 Attack Scenarios 14.3.2.1 Scenario #1: Near IM Relay Servers 14.3.2.2 Scenario #2: Border Gateway 14.4 COLD: COmmunication Link De-anonymization 14.4.1 Architecture 14.4.2 Details 14.4.2.1 Discrete Wavelet Transform 14.4.2.2 Choosing the Optimal Number of Decomposition Levels 14.4.2.3 Coefficient Feature Vector 14.4.2.4 Correlation 14.4.2.5 Candidate Set Generation 14.4.3 Example 14.5 Experimental Results 14.5.1 Data Set 14.5.1.1 Input Data 14.5.1.2 Ground Truth Data 14.5.2 Evaluation Metrics 14.5.3 Results 14.5.4 Discussions 14.6 Evasion and Countermeasures 14.7 Conclusions References