Protecting Privacy through Homomorphic Encryption

Preface
	References
Contents
Part I Introduction to Homomorphic Encryption
	Introduction to Homomorphic Encryption and Schemes
		1 Introduction to Homomorphic Encryption
			1.1 Plaintexts and Operations
			1.2 Vectors and Special-Purpose Plaintext Data Types
			1.3 Ciphertexts
			1.4 Symmetric vs. Public-Key Homomorphic Encryption
			1.5 Parameters and Security
		2 The BGV and BFV Encryption Schemes
			2.1 Homomorphic Operations
				Two-Argument Operations
				Unary Operations
			2.2 Parameter Selection
			2.3 A BGV/BFV Hello World Example
			2.4 Further Information
				Maintenance Operations
				Evaluation Keys
				Data Encoding
				Data Movement Operations
				References for the BFV Encryption Scheme
				References for the BGV Encryption Scheme
		3 The CKKS Encryption Scheme
			3.1 Homomorphic Operations
				Two-Argument Operations
				Unary Operations
			3.2 Parameter Selection
			3.3 A CKKS Hello World Example
			3.4 Further Information
				Data Encoding
				Maintenance Operations
				Evaluation Keys
				References for the CKKS Scheme
				Reference Implementations
		4 The DM (FHEW) and CGGI (TFHE) Schemes
			4.1 Basic Concepts
			4.2 Homomorphic Operations
				Simple Mode Plaintext Space and Operations
				A DM/CGGI Hello World Example (Using Simple Mode)
				Advanced Mode Plaintext Space and Operations
				Advanced-Mode CGGI Hello World Example (Corresponds to the DFA in Fig. 1)
			4.3 Further Information
				Advanced Notes on Parameters
				Some More Advanced Operations Are Supported
				Maintenance Operations (and More)
				Advanced Functionality in the CGGI Encryption Scheme
				Difference Between DM and CGGI
				Variants of DM/CGGI
				Scheme Switching Using CGGI
				Reference Implementations
		References
Part II Homomorphic Encryption Security Standard
	Homomorphic Encryption Standard
		1 Homomorphic Encryption Standard Section 1: Recommended Encryption Schemes
			1.1 Notation and Definitions
			1.2 Properties
			1.3 The BGV and B/FV Homomorphic Encryption Schemes
			1.4 The GSW Scheme and Bootstrapping
			1.5 Other Schemes
			1.6 Additional Features & Discussion
		2 Homomorphic Encryption Standard Section 2: Recommended Security Parameters
			2.1 Hard Problems
			2.2 Attacks on LWE and Their Complexity
			2.3 The Arora-Ge Attack
			2.4 Algebraic Attacks on Instances of Ring-LWE
			2.5 Secure Parameter Selection for Ring LWE
			Organizers
			Contributors
		References
			Software References for 7 Homomorphic Encryption Libraries
Part III Applications of Homomorphic Encryption
	Privacy-Preserving Data Sharing and Computation Across Multiple Data Providers with Homomorphic Encryption
		1 Motivation
		2 System Models and Use Cases
		3 Stakeholders and Functionalities
		4 Functionality Goals
		5 Threat Models and Security Requirements
		6 High-Level Workflow
		7 Example Protocol Instantiations
			7.1 Distributed Data Discovery (MedCo)
				Setup
				Initialization
				ETL Process
				Query Generation
				Query Re-encryption
				Local Query Processing
				Result Obfuscation
				Result Shuffling
				Proxy Re-encryption of the Result
				Decryption
			7.2 Centralized Data Analysis (Private Evaluation of Random Forests)
			7.3 Distributed Data Analysis (Statistical Computation and Training of Machine Learning Models)
		8 Concluding Remarks
		References
	Secure and Confidential Rule Matching for Network Traffic Analysis
		1 Introduction
			1.1 Motivation and Business Problem
		2 Threat Model
		3 Protocol
			3.1 Client
			3.2 Solution Provider
			3.3 Rule Sets
				Examples of Rules
			3.4 Prerequisites of the Protocol
			3.5 Protocol Steps
		4 Performance, Usability, and Scalability
			4.1 Security Agencies
			4.2 Fraud Detection
		References
	Trusted Monitoring Service (TMS)
		1 Privacy-Preserving Health Monitoring
		2 Business Motivation
		3 Protocol (Workflow)
		4 Performance, Usability, Scalability
		5 Applications of Trusted Monitoring Systems
		References
	Private Set Intersection and Compute
		1 Motivation
			1.1 Privacy Compliance
			1.2 Co-marketing as a Use Case
		2 Application Functionality
			2.1 Database Statistics on PSI Selected Entries
		3 Protocol
			3.1 Workflow
			3.2 First Protocol: N Parties with One Central Compute Node
		4 Examples
			4.1 IXUP
			4.2 Private Join and Compute
		5 Performance, Usability, and Scalability
		References
Part IV Applications of Homomorphic Encryption
	Private Outsourced Translation for Medical Data
		1 Introduction
		2 Machine Translation
		3 Design
			3.1 Challenges
		4 Implementation and Evaluation
			4.1 Encoding
			4.2 Optimizations
			4.3 Results
		5 Discussion
		References
	HappyKidz: Privacy Preserving Phone Usage Tracking
		1 Introduction
			1.1 Privacy Model
		2 Proof of Concept Implementation
			2.1 Data Selection and Features
			2.2 Learning Model
			2.3 Microsoft SEAL Implementation
		3 Soundness and Future Work
			3.1 Future Work
		4 Conclusion
		References
	i-SEAL2: Identifying Spam EmAiL with SEAL
		1 Introduction
		2 Private Classification
		3 Private Training
		4 Conclusion
	PRIORIS: Enabling Secure Detection of Suicidal Ideation from Speech Using Homomorphic Encryption
		1 Introduction
		2 Suicide Ideation Detection
			2.1 Dataset
			2.2 Application
		3 Use Cases
			3.1 Use-Case 1: Secure Detection and Response
			3.2 Use-Case 2: Secure Clinical Assessment Assistance
			3.3 Use-Case 3: Secure Treatment Evaluation
		4 Network Training
		5 Homomorphic Network Evaluation
		6 Extensions and Future Work
		7 Conclusion
		References
	Gimme That Model!: A Trusted ML Model Trading Protocol
		1 Introduction
		2 Non-cryptographic Approaches and Their Drawbacks
		3 Our HE-Based Cryptographic Solution
			3.1 The Protocol
			3.2 Efficiency of the Protocol
			3.3 Towards the Perfect Model Protection
			3.4 Compatible ML Models
		4 Discussions
			4.1 Plausibility of Trading ML Models
			4.2 Alternative Cryptographic Solutions
			4.3 Dual Scenario: Trading Datasets
		References
	HEalth: Privately Computing on Shared Healthcare Data
		1 Introduction and Motivation
		2 Our Scenario
		3 A Discussion of the Underlying Cryptography
		4 The Initial Goal: Fairness
		5 Discussion
		References
	Private Movie Recommendations for Children
		1 Introduction
			1.1 Background
		2 Proposed Implementation
			2.1 HE Technical Details
		3 Discussion
		References
	Privacy-Preserving Prescription Drug Management Using Fully Homomorphic Encryption
		1 Introduction
		2 Our Model
		3 Fully Homomorphic Encryption
			3.1 Our Choice of FHE Scheme
			3.2 Updating the Encrypted Records
			3.3 Parameters
		4 The Machine Learning Model
			4.1 Training the Model
			4.2 A Remark on Using ML
		5 Authentication
			5.1 The Shared Secret Key
			5.2 Prevent Patient Tampering
		References