Codes, Cryptology and Information Security. 4th International Conference, C2SI 2023 Rabat, Morocco, May 29–31, 2023 Proceedings

Preface
Organization
C2SI Conference in Honor of Jean-Louis Lanet
Contents
Invited Papers
Cryptologists Should Not Ignore the History of Al-Andalusia
	1 Introduction
	2 Earlier Viewpoints
	3 Closed Research
		3.1 Some Al-Andalusian History
		3.2 Comparing the Two Worlds
	4 Using Information Flow to Analyze ``Leaks\'\'
		4.1 Some Heuristic Arguments
		4.2 Information Flow in Crypto Context
	5 ``Open\'\' Research
		5.1 How Anthropology Can Help
		5.2 Condoned Research
		5.3 The Crypto Context
	6 Conclusions
	References
Compact Post-quantum Signatures from Proofs of Knowledge Leveraging Structure for the PKP, SD and RSD Problems
	1 Introduction
	2 Preliminaries
		2.1 Proof of Knowledge and Commitment Schemes
		2.2 Coding Theory
		2.3 Hard Problems
	3 New Paradigm to Design PoK Leveraging Structure
		3.1 Overview of Our PoK Leveraging Structure Approach
		3.2 Properties of PoK Leveraging Structure
	4 Amplifying Challenge Space to Mitigate ch2KZ20 Attack
		4.1 Overview of Our Challenge Space Amplification Technique
		4.2 The ch2KZ20 Attack Against 5-Round PoK
		4.3 Trade-Off Between Public Key Size and Challenge Space Size
	5 New PoK with Helper for the SD Problem
	6 New PoK Related to the PKP, SD and RSD Problems
		6.1 PoK Leveraging Structure for the IPKP Problem
		6.2 PoK Leveraging Structure for the QCSD Problem over F2
		6.3 PoK Leveraging Structure for the IRSL Problem
	7 Resulting Signatures and Comparison
		7.1 Signatures Based on PoK Related to the PKP Problem
		7.2 Signatures Based on PoK Related to the SD Problem
		7.3 Signatures Based on PoK Related to the RSD/RSL Problem
	8 Conclusion
	A Proof of Theorem 1
	B Proof of Theorem 2
	C Proof of Theorem 3
	D Proof of Theorem 4
	E PoK Leveraging Structure Related to the MQ Problem
	F PoK Leveraging Structure Related to SD over Fq
	References
On Catalan Constant Continued Fractions
	1 Introduction
	2 The Initial Conjectures
	3 Notations
	4 The Generalized Formulae
		4.1 =0
		4.2 =1
		4.3 =2
		4.4 =3
		4.5 =4
		4.6 =5
		4.7 =6
		4.8 =7 and Beyond
		4.9 Other G Relations of the Ramanujan Machine Project
		4.10 Further Extensions
	References
Cryptography
Full Post-Quantum Datagram TLS Handshake in the Internet of Things
	1 Introduction
	2 Building Blocks
		2.1 Digital Signatures and Certification
		2.2 Key Encapsulation Mechanisms
		2.3 NIST Post-Quantum Standardization
		2.4 Datagram Transport Layer Security
	3 Related Work
	4 Full Post-Quantum DTLS Handshake in IoT
		4.1 Design and Environment Considerations
		4.2 PQ Digital Signature Scheme Selection
		4.3 PQ Key Encapsulation Mechanism Selection
		4.4 Full PQ DTLS 1.3 Handshake Implementation
	5 Discussion
	6 Conclusion
	References
Moderate Classical McEliece Keys from Quasi-Centrosymmetric Goppa Codes
	1 Introduction
	2 Coding Theory Background
	3 Goppa Codes in Cauchy and Symetric Centrosymmetric Form
		3.1 Building a Binary Goppa Code in Centrosymmetric Form
		3.2 Constructing Quasi-Centrosymmetric Subfield Subcodes
	4 Protocol Specification
		4.1 Parameters
		4.2 New Key Generation
	5 Security
		5.1 Key Recovery Attacks
		5.2 Decoding Attacks
		5.3 Parameter Selection
	References
QCB is Blindly Unforgeable
	1 Introduction
	2 Evolution of Unforgeability Notions
	3 QCB: Post-Quantum Secure Authenticated Encryption
	4 QCB is Blindly Unforgeable
	5 General Blindly Unforgeable Authenticated Encryption
	6 Conclusion and Future Work
	A Quantum Attacks Against Symmetric Cryptography
	B Instantiation of QCB with TRAX and Pholkos
	References
A Side-Channel Secret Key Recovery Attack on CRYSTALS-Kyber Using k Chosen Ciphertexts
	1 Introduction
	2 Previous Work
	3 CRYSTALS-Kyber Algorithm
	4 Single Chosen Ciphertext Attack Method
		4.1 Intuitive Idea
		4.2 Selecting Secret Key-Related Intermediate Variables
		4.3 Chosen Ciphertext Construction Method
	5 Profiling Stage
		5.1 Equipment
		5.2 Trace Acquisition
		5.3 Leakage Analysis
		5.4 MLP Model Training
	6 Attack Stage
	7 Experimental Results
	8 Conclusion
	References
A New Keyed Hash Function Based on Latin Squares and Error-Correcting Codes to Authenticate Users in Smart Home Environments
	1 Introduction
		1.1 Motivation
		1.2 Preliminaries
	2 Definitions and Notations
	3 Protocol of the Hash Function
	4 Properties of the Hash Function
	5 Application in Smart Home Environment
	6 Security of the Smart Door System
	7 Conclusion and Future Work
	References
Attack on a Code-Based Signature Scheme from QC-LDPC Codes
	1 Introduction
	2 Preliminaries
		2.1 Notations
		2.2 MPT Signature Scheme
	3 Deciding Between Two Bernoulli Distributions
		3.1 Deciding a Distribution via Threshold Criterion
		3.2 Repeated Uses of the Threshold Criterion
	4 The Proposed Attack on MPT Signature
		4.1 Partial Key Recovery Attack
		4.2 Forgery Attack
	5 Experimental Results
	6 Conclusion
	References
Computational Results on Gowers U2 and U3 Norms of Known S-Boxes
	1 Preliminaries
	2 Results and Observations
	3 Conclusion
	References
Multi-input Non-interactive Functional Encryption: Constructions and Applications
	1 Introduction
		1.1 Fully Decentralization in Computing over Encrypted Data: MINI-FE
		1.2 Our Results: MINI-FE for the IP Functionality
	2 Applications of MINI-FE for IP
	3 Definitions
		3.1 MINI-FE
		3.2 Bilinear Maps
	4 MINI-FE for Inner Products
	5 Security of the Protocol
		5.1 Efficiency Analysis
	References
Indifferentiability of the Confusion-Diffusion Network and the Cascade Block Cipher
	1 Introduction
		1.1 Our Contribution
		1.2 Games for Indifferentiable Security
	2 Definition of CDN
		2.1 Attack Against CDN2, 2
		2.2 Our Attack
		2.3 Analysis of the Attack
	3 Attacks on Three Round Cascade with Two Keys
		3.1 Definitions
		3.2 Our Distinguisher D
		3.3 Analysis of Attack
		3.4 Probability Analysis
	4 Conclusion
	References
Quantum Cryptanalysis of 5 Rounds Feistel Schemes and Benes Schemes
	1 Introduction
	2 Feistel and Benes Constructions
		2.1 Feistel Scheme
		2.2 Benes Scheme
	3 Overview of Cryptanalysis on Feistel Schemes
	4 Quantum Collision
	5 Quantum Cryptanalysis on Feistel Network
	6 Quantum Distinguishing Attack on Benes Scheme
	References
Lattice-Based Accumulator with Constant Time List Update and Constant Time Verification
	1 Introduction
		1.1 History of Accumulator
		1.2 Accumulator Based on Lattice-Based Problem
		1.3 Contribution
		1.4 Paper Organization
	2 Preliminary
	3 Previous Research
		3.1 A Signature Scheme Based on the Partial Fourier Recovery Problem ch14HPSSW14
		3.2 Aggregate Signature Scheme Based on Partial Fourier Recovery Problem ch14DHSS20
	4 Proposed Constant Lattice-Based Accumulator
		4.1 Unforgeability of HPSSW Signature
		4.2 Our Proposed Accumulator
		4.3 Update Method in the Proposed Accumulator
		4.4 Analysis of Our Proposed Accumulator
	5 Comparison
	6 Conclusion
	References
Information Security
Malicious JavaScript Detection Based on AST Analysis and Key Feature Re-sampling in Realistic Environments
	1 Introduction
	2 Related Techniques
		2.1 Feature Extraction Using Natural Language Processing
		2.2 Representing JavaScript Code in AST Form
		2.3 K-means Clustering Algorithm
	3 Related Works
		3.1 Training Model with an Imbalanced Dataset
		3.2 Analysis of Malicious JavaScript Detection
	4 Proposed Method
		4.1 Outline
		4.2 Feature Reduction and Pattern Replacement
		4.3 Feature Extraction Using Doc2Vec
		4.4 Oversampling Malicious Data with Random Seed Oversampling
		4.5 Evaluate Trained Model on Test Dataset
	5 Evaluation
		5.1 Dataset
		5.2 Experiment
		5.3 Implementation
		5.4 Result
	6 Discussion
		6.1 The Effectiveness of the Feature Reduction Methods
		6.2 Comparison of Different Classifier Models
		6.3 Difficulties in Comparing to Other Studies
		6.4 Limitations
		6.5 Effectiveness of AST Parsing
	7 Conclusion
	References
Searching for Gemstones: Flawed Stegosystems May Hide Promising Ideas
	1 Introduction
	2 Preliminaries
		2.1 Notations
		2.2 Image Compression
		2.3 The J3 Steganographic Algorithm
	3 Main Results
		3.1 Adding a Pre-processing Step
		3.2 Taking Advantage of Each Channel\'s Embedding Capacity
		3.3 Security Aspects
	4 Implementation
		4.1 Implementation Results
	5 Conclusions and Future Work
	A  Pseudocode
	B  A Steganography Application Proposal
	References
A Study for Security of Visual Cryptography
	1 Introduction
	2 Visual Cryptography
		2.1 Outline ch17DBLP:confspseurocryptspsNaorS94
		2.2 Information-Theoretic Security of VC
	3 Pseudo-random Permutation
	4 Attack Algorithm
	5 Detailed Attack Scenario
	6 Statistical Property of PRP
		6.1 Preliminary
		6.2 Computer Experiment and Results
	7 Conclusion
	References
Forecasting Click Fraud via Machine Learning Algorithms
	1 Introduction
	2 Methodology
		2.1 General Overview
		2.2 Data Description
		2.3 Imbalanced Data
		2.4 XGBoost Model
		2.5 Evaluation Metrics
		2.6 Normalization
		2.7 Data-Split
	3 Experiment and Analysis
		3.1 Feature Engineering
		3.2 Hyper Parameter Tuning
		3.3 Experiment Results
	4 Discussion
	5 Conclusion
	References
An Enhanced Anonymous ECC-Based Authentication for Lightweight Application in TMIS
	1 Introduction
		1.1 Threat Model
		1.2 Motivation and Contribution
		1.3 Paper Organization
	2 Related Works
	3 Review and Cryptanalysis of Ostad-Sharif et al.\'s Scheme
		3.1 Review of Ostad-Sharif et al.\'s Scheme
		3.2 Cryptanalysis of Ostad-Sharif et al.\'s Scheme
	4 Proposed Scheme
		4.1 Registration Phase
		4.2 Login and Authentication Phase
	5 Informal Security Analysis
		5.1 Perfect Forward Secrecy
		5.2 Known Key Security
		5.3 Session Key Verification
		5.4 Anonymity and Unlinkability
		5.5 Stolen Smart Device Attack
		5.6 Offline Password Guessing Attack
		5.7 Replay Attack
		5.8 Man-in-the-Middle (MITM) Attack
		5.9 Key Replicating Attack
		5.10 Privileged Insider Attack
		5.11 Patient and Server Impersonation Attacks
		5.12 Denial of Service (DoS) Attack
		5.13 Cloud Server Compromise Attack
		5.14 Key Compromise Password Guessing Attack
		5.15 Key Compromise Impersonation Attack
	6 Formal Security Verification Using AVISPA
	7 Performance Evaluation
		7.1 Comparison of Security Features
		7.2 Computation and Communication Cost
		7.3 Storage Cost
		7.4 Impact of Network Throughput
	8 Conclusion
	References
Discrete Mathematics
Symmetric 4-Adic Complexity of Quaternary Generalized Cyclotomic Sequences of Order Four with Period 2pn
	1 Introduction
	2 Preliminaries
	3 Properties of the Generating Polynomial of Sequences
		3.1 Subsidiary Lemmas
	4 Generalized Gauss Periods
		4.1 Properties of Generalized Gauss Periods
	5 4-Adic Complexity
	6 Symmetric 4-Adic Complexity
	7 Conclusion
	References
Weightwise Perfectly Balanced Functions and Nonlinearity
	1 Introduction
	2 Preliminaries
		2.1 Boolean Functions and Weightwise Considerations
		2.2 Symmetric Functions
		2.3 Weightwise Perfectly Balanced Functions
		2.4 Krawtchouk Polynomials and Properties
	3 Bounds on the Nonlinearity of a WPB Function
	4 Constructions of WPB Functions with Prescribed Nonlinearity
		4.1 Concrete Examples in 8 and 16 Variables
	5 Distribution of the Nonlinearity of WPB Functions
		5.1 Experimental Approximation of Nn for n=8 and 16
	6 Conclusion
	A  Approximation of N16
	References
Chudnovsky-Type Algorithms over the Projective Line Using Generalized Evaluation Maps
	1 Introduction
	2 Chudnovsky-Type Multiplication Algorithms
		2.1 Background and Notations
		2.2 The Algorithm
		2.3 Chudnovsky-Type Algorithms over the Projective Line
	3 Chudnovsky-Type Algorithms over the Projective Line Using Generalized Evaluation Maps
	4 Multiplication of Truncated Local Expansions Using Chudnovsky-Type Algorithms over the Projective Line
	5 A Better Construction Strategy
		5.1 Generic Strategy
		5.2 Experimental Results
	References
Coding Theory
Security Enhancement Method Using Shortened Error Correcting Codes
	1 Introduction
	2 Preliminaries
		2.1 Linear Code
		2.2 LDPC and MDPC Codes
		2.3 Shortened LDPC Codes
	3 Proposal Method
		3.1 Basic Idea
		3.2 Proposed Method
	4 Security Evaluation
		4.1 Security Model
		4.2 Detailed Evaluation
		4.3 Results of Security Evaluation
	5 Application to Two-Way Cryptographic Communication Under High Noise Environment
	6 Application for Asymmetric Key Cryptography
		6.1 Motivation and Background
		6.2 Proposed Method
		6.3 Security Evaluation (2)
		6.4 Application to One-Way Cryptographic Communication Under High Noise Environment
	7 Conclusions
	References
An Updated Database of Z4 Codes and an Open Problem About Quasi-cyclic Codes
	1 Introduction and Motivation
	2 Basic Definitions
	3 Cyclic Search over Z4
	4 ASR Search Method for New QC Codes
		4.1 Adapting the ASR Algorithm for Free QC Codes over Z4
		4.2 Adapting ASR for Non-free QC Codes and an Open Problem
	5 New Linear Codes over Z4
	6 Conclusion and Further Research
	References
Author Index