Showing 1–42 of 42 results for author: Chen, A C H

Quantum-Safe Web Service Architecture Using Time-Based One-Time Passwords

Authors: Abel C. H. Chen

Abstract: One-Time Passwords (OTPs) have become a common option for multi-factor authentication in several applications. For instance, during website login processes, OTPs are often used in conjunction with traditional text-based usernames and passwords to verify whether the access request originates from a legitimate human user rather than an automated agent. However, in scenarios involving automated conne… ▽ More One-Time Passwords (OTPs) have become a common option for multi-factor authentication in several applications. For instance, during website login processes, OTPs are often used in conjunction with traditional text-based usernames and passwords to verify whether the access request originates from a legitimate human user rather than an automated agent. However, in scenarios involving automated connections and system-to-system interoperability, Time-Based One-Time Passwords (TOTPs) may be required to establish secure connections and access Web Services (WSs). Therefore, this study focuses on exploring the development of a quantum-safe web service architecture. The proposed approach achieves transmission security management by implementing Transport Layer Security (TLS) and HyperText Transfer Protocol Secure (HTTPS) based on Post-Quantum Cryptography (PQC). Furthermore, web service security management is realized through the construction of keyed-Hash Message Authentication Code (HMAC)-driven TOTPs. Within the experimental environment, this study evaluates and compares the computational performance of the Secure Hash Algorithm-2 (SHA-2), SHA-3, Ascon-Hash256, and SM3. The required computation time under different hardware resource conditions is analyzed for future web service deployment. △ Less

Submitted 17 August, 2026; originally announced August 2026.

Multivariate Cryptography-Based Anonymous Certificate Scheme

Authors: Abel C. H. Chen

Abstract: As quantum computing technology continues to mature, the US National Institute of Standards and Technology (NIST) has outlined a migration timeline for Post-Quantum Cryptography (PQC), recommending the deprecation of certain elliptic curve cryptography (ECC) by 2030. Furthermore, privacy-sensitive application scenarios, such as vehicular communications, require the use of anonymous certificates. H… ▽ More As quantum computing technology continues to mature, the US National Institute of Standards and Technology (NIST) has outlined a migration timeline for Post-Quantum Cryptography (PQC), recommending the deprecation of certain elliptic curve cryptography (ECC) by 2030. Furthermore, privacy-sensitive application scenarios, such as vehicular communications, require the use of anonymous certificates. However, existing anonymous certificate schemes are still largely based on ECC. Therefore, this study proposes a multivariate cryptography-based anonymous certificate scheme, aiming to design quantum-safe anonymous certificates suitable for privacy-sensitive application services. The proposed multivariate cryptography-based anonymous certificate scheme is supported by rigorous mathematical proofs and illustrated with computational cases. △ Less

Submitted 15 July, 2026; originally announced July 2026.

Pseudonym Scheme Based on Hybrid Certificates for Security Credential Management System in Vehicular Communications

Authors: Abel C. H. Chen, F. J. Hwang, Yu-Chih Wei, Chin-Chen Chang, Bon-Yeh Lin

Abstract: In recent years, the Institute of Electrical and Electronics Engineers (IEEE) and the European Telecommunications Standards Institute (ETSI) have developed a series of security communication standards for vehicular communications. These standards include mechanisms such as the Security Credential Management System (SCMS) and Butterfly Key Expansion (BKE) to protect vehicle privacy. However, these… ▽ More In recent years, the Institute of Electrical and Electronics Engineers (IEEE) and the European Telecommunications Standards Institute (ETSI) have developed a series of security communication standards for vehicular communications. These standards include mechanisms such as the Security Credential Management System (SCMS) and Butterfly Key Expansion (BKE) to protect vehicle privacy. However, these standards are mainly based on the Elliptic-Curve Cryptography (ECC), which may be vulnerable to attacks from quantum computing in the future. In response to this potential risk, this study proposes a hybrid certificate that combines the ECC with Post-Quantum Cryptography (PQC). This approach enables infrastructure systems to be built on cryptographic foundations that are more resilient to quantum-based attacks. Furthermore, this study presents a generalized pseudonym scheme that is compatible with various cryptographic algorithms for generating pseudonym certificates. This design aims to eliminate the possibility of inferring any correlation between the public key in a pseudonym certificate and that in an enrollment certificate. This study also conducts a comprehensive performance evaluation of the RSA, ECC, and PQC algorithms, particularly those standardized by the National Institute of Standards and Technology (NIST). The comparison considers factors such as message length and computation time. Based on the findings, this study recommends suitable pseudonym schemes that adopt hybrid certificates for secure and efficient use in vehicular communications. △ Less

Submitted 11 June, 2026; originally announced June 2026.

Journal ref: IEEE Canadian Journal of Electrical and Computer Engineering (2026)

Key Encapsulation Mechanism-Based Integrated Encryption Scheme (KEM-IES)

Authors: Abel C. H. Chen

Abstract: The Elliptic Curve Integrated Encryption Scheme (ECIES) is widely regarded as a practical method and has been adopted by multiple standards. However, the advancement of quantum computing technologies poses potential security risks to ECIES. Therefore, this study proposes a Key Encapsulation Mechanism-Based Integrated Encryption Scheme (KEM-IES), which enhances resistance to quantum attacks by inco… ▽ More The Elliptic Curve Integrated Encryption Scheme (ECIES) is widely regarded as a practical method and has been adopted by multiple standards. However, the advancement of quantum computing technologies poses potential security risks to ECIES. Therefore, this study proposes a Key Encapsulation Mechanism-Based Integrated Encryption Scheme (KEM-IES), which enhances resistance to quantum attacks by incorporating a Post-Quantum Cryptography (PQC)-based Key Encapsulation Mechanism (KEM). Furthermore, the study integrates the Ascon algorithm, released by the National Institute of Standards and Technology (NIST) in August 2025, to further improve computational efficiency and enable applicability to embedded systems. The proposed KEM-IES and its Ascon-based variant are implemented on a Raspberry Pi 4, and evaluations are conducted to compare the performance of ECIES and KEM-IES. △ Less

Submitted 11 May, 2026; originally announced May 2026.

Post-Quantum Cryptography-Based Bidirectional Authentication Key Exchange Protocol and Industry Applications: A Case Study of Instant Messaging

Authors: Abel C. H. Chen, James W. H. Tung, Austin B. Y. Lin, Chin-Ling Chen, Ching-Chun Chang, Chin-Chen Chang

Abstract: This study aims to enhance the bidirectional authentication capability of ML-KEM (Module-Lattice-Based Key-Encapsulation Mechanism) by proposing the post-quantum cryptography-based (PQC-based) bidirectional authentication key exchange protocol. Furthermore, it introduces dual-usage certificates combining PQC-based DSA (Digital Signature Algorithm) and PQC-based KEM, which include composite schemes… ▽ More This study aims to enhance the bidirectional authentication capability of ML-KEM (Module-Lattice-Based Key-Encapsulation Mechanism) by proposing the post-quantum cryptography-based (PQC-based) bidirectional authentication key exchange protocol. Furthermore, it introduces dual-usage certificates combining PQC-based DSA (Digital Signature Algorithm) and PQC-based KEM, which include composite schemes, catalyst schemes, and chameleon schemes. These dual-usage certificates utilize the PQC-based DSA public key and PQC-based KEM public key within the certificate to meet the requirements for bidirectional authentication and encryption, enabling the negotiation of a shared secret key. During the experimental phase, the study validates and compares key exchange message lengths and computation times under different certificate configurations. Finally, instant messaging is presented as an industry application to demonstrate the practical implementation of the proposed protocol. △ Less

Submitted 8 April, 2026; originally announced April 2026.

Comments: This study was presented at the NIST Workshop on Guidance for KEMs and is available at the following link: https://csrc.nist.gov/csrc/media/Events/2025/workshop-on-guidance-for-kems/documents/papers/pqc-based-bidirectional.pdf

Comparison of Credential Management Systems Based on the Standards of IEEE, ETSI, and YD/T 3957-2021

Authors: Abel C. H. Chen

Abstract: As V2X (Vehicle-to-Everything) technology becomes increasingly prevalent, the security of V2X networks has garnered growing attention worldwide. In North America, the IEEE 1609 series standards are primarily used, while Europe adopts the ETSI series standards, and China has also established its industry standard, YD/T 3957-2021, among others. Although these standards share some commonalities, they… ▽ More As V2X (Vehicle-to-Everything) technology becomes increasingly prevalent, the security of V2X networks has garnered growing attention worldwide. In North America, the IEEE 1609 series standards are primarily used, while Europe adopts the ETSI series standards, and China has also established its industry standard, YD/T 3957-2021, among others. Although these standards share some commonalities, they also exhibit differences. To achieve compatibility across these standards, analyzing their similarities and differences is a crucial issue. Therefore, this study focuses on analyzing the three major standards mentioned above, discussing aspects such as certificate formats, signed message formats, and certificate request processes. Additionally, this research evaluates the efficiency of different cryptographic methods, including NIST P-256 and SM2-256, SHA-256 and SM3-256, as well as AES-128 and SM4-128. Finally, the study implements these three major standards on V2X devices and compares the efficiency of message signing and signature verification in V2X systems, providing a reference for the development of a secure certificate management system for V2X networks. △ Less

Submitted 2 March, 2026; originally announced March 2026.

Implementation Challenges in Quantum Key Distribution

Authors: Abel C. H. Chen

Abstract: In recent years, quantum computing technologies have steadily matured and have begun to find practical applications across various domains. One important area is network communication security, where Quantum Key Distribution (QKD) enables communicating parties to establish a shared secret that can then be used to generate symmetric keys for subsequent encryption and decryption. This study focuses… ▽ More In recent years, quantum computing technologies have steadily matured and have begun to find practical applications across various domains. One important area is network communication security, where Quantum Key Distribution (QKD) enables communicating parties to establish a shared secret that can then be used to generate symmetric keys for subsequent encryption and decryption. This study focuses on implementing and comparing two well-known QKD protocols, namely BB84 and E91, within an actual quantum computing environment. It also proposes the use of SX gate operations to generate uniform quantum superposition states. By leveraging the properties of quantum superposition and quantum entanglement, the study illustrates how communicating parties can securely obtain a shared secret while preventing adversaries from intercepting it. The experiments are conducted using the IBM Quantum Platform to demonstrate the feasibility of the BB84 and E91 protocols on actual quantum hardware. The evaluation considers several metrics, including entropy, Independent and Identically Distributed (IID), and error-rate verifications. △ Less

Submitted 1 February, 2026; originally announced February 2026.

Comments: in Chinese

Post-Quantum Cryptography Key Expansion Method and Anonymous Certificate Scheme Based on NTRU

Authors: Abel C. H. Chen

Abstract: NTRU is one of the important lattice-based post-quantum cryptography methods, offering resistance against quantum computing attacks. However, a drawback of NTRU lies in its relatively low efficiency in generating key pairs. Therefore, this study proposes an NTRU-based key expansion method that enables efficient public key expansion. Furthermore, the proposed method is applied to an anonymous certi… ▽ More NTRU is one of the important lattice-based post-quantum cryptography methods, offering resistance against quantum computing attacks. However, a drawback of NTRU lies in its relatively low efficiency in generating key pairs. Therefore, this study proposes an NTRU-based key expansion method that enables efficient public key expansion. Furthermore, the proposed method is applied to an anonymous certificate scheme, allowing an end entity to generate a key pair only once, after which the certificate authority can expand multiple distinct public keys for anonymity. The experimental results demonstrate that the proposed key expansion method achieves significantly higher efficiency than key pair generation. △ Less

Submitted 1 January, 2026; originally announced January 2026.

Comments: in Chinese language

Deterministic Random Bit Generators Based on Ascon for Embedded Systems

Authors: Abel C. H. Chen

Abstract: As the Deterministic Random Bit Generator (DRBG) serves as a fundamental component in random number generation and cryptographic applications, its performance and security are particularly critical in resource-constrained embedded systems, where memory capacity and computational efficiency are limited. Establishing a high-performance and secure DRBG is therefore an important issue for embedded sys… ▽ More As the Deterministic Random Bit Generator (DRBG) serves as a fundamental component in random number generation and cryptographic applications, its performance and security are particularly critical in resource-constrained embedded systems, where memory capacity and computational efficiency are limited. Establishing a high-performance and secure DRBG is therefore an important issue for embedded system design. Furthermore, the National Institute of Standards and Technology (NIST) established the Ascon lightweight cryptographic standard in August 2025, which is suitable for use in resource-limited embedded environments. Therefore, this study revises the DRBG standard and proposes three Ascon-driven constructions: the Ascon-Driven Hash-Based DRBG, the Ascon-Driven keyed-Hash Message Authentication Code (HMAC) DRBG, and the Ascon-Driven Counter-mode (CTR) DRBG. In the experiments, these methods are implemented on a Raspberry Pi platform. The experimental results demonstrate that the proposed approaches achieve higher computational efficiency and lower memory usage compared with existing DRBG implementations, making them suitable for deployment in embedded systems. △ Less

Submitted 30 November, 2025; originally announced December 2025.

Comments: in Chinese language

A Comparative Study of Hybrid Post-Quantum Cryptographic X.509 Certificate Schemes

Authors: Abel C. H. Chen

Abstract: As quantum computing hardware continues to advance, the integration of such technology with quantum algorithms is anticipated to enable the decryption of ciphertexts produced by RSA and Elliptic Curve Cryptography (ECC) within polynomial time. In response to this emerging threat, the U.S. National Institute of Standards and Technology (NIST) finalized a series of Post-Quantum Cryptography (PQC) st… ▽ More As quantum computing hardware continues to advance, the integration of such technology with quantum algorithms is anticipated to enable the decryption of ciphertexts produced by RSA and Elliptic Curve Cryptography (ECC) within polynomial time. In response to this emerging threat, the U.S. National Institute of Standards and Technology (NIST) finalized a series of Post-Quantum Cryptography (PQC) standards in August 2024 and outlined a roadmap for PQC migration. Consequently, the design of X.509 certificates that adhere to PQC standards has become a crucial focus in the development of certificate management systems. To further strengthen security and facilitate a smooth migration process, several hybrid certificate schemes have been proposed internationally based on the X.509 certificate format, including the composite scheme, the catalyst scheme, and the chameleon scheme. This study presents a comprehensive analysis and comparison of these hybrid certificate schemes from multiple perspectives (e.g., certificate size, computational efficiency, and migration feasibility) to assess their suitability for various applications and services. △ Less

Submitted 30 October, 2025; originally announced November 2025.

Comments: in Chinese language

Hybrid Schemes of NIST Post-Quantum Cryptography Standard Algorithms and Quantum Key Distribution for Key Exchange and Digital Signature

Authors: Abel C. H. Chen

Abstract: Since the security of post-quantum cryptography (PQC) algorithms is based on the hardness of mathematical problems, while the security of quantum key distribution (QKD) relies on the fundamental principles of quantum physics, each approach possesses distinct advantages and limitations that can complement one another. Consequently, recent studies have proposed hybrid schemes that combine QKD and PQ… ▽ More Since the security of post-quantum cryptography (PQC) algorithms is based on the hardness of mathematical problems, while the security of quantum key distribution (QKD) relies on the fundamental principles of quantum physics, each approach possesses distinct advantages and limitations that can complement one another. Consequently, recent studies have proposed hybrid schemes that combine QKD and PQC to establish a dual-layered security model. In response to this trend, this study proposes hybrid schemes that integrate QKD with the National Institute of Standards and Technology (NIST) standardized PQC algorithms. These hybrid schemes include two core components: a hybrid QKD-PQC key exchange protocol and a hybrid QKD-PQC digital signature scheme. For the hybrid key exchange protocol, this study combines Module-Lattice-based Key Encapsulation Mechanisms (ML-KEM) with QKD protocols, specifically BB84 and E91, to construct a secure key exchange protocol. In the design of the hybrid digital signature scheme, this study utilizes Module-Lattice-based Digital Signature Algorithms (ML-DSA) and Stateless Hash-based Digital Signature Algorithms (SLH-DSA) to generate signature reconstruction values. These values are verified using confirmation codes transmitted via the BB84 and E91 protocols. The proposed hybrid key exchange protocol is evaluated by examining the shared secret key it produces, particularly with respect to entropy and whether the output is independent and identically distributed (IID). Furthermore, the computation time and message lengths of the proposed hybrid schemes are evaluated. △ Less

Submitted 30 September, 2025; originally announced October 2025.

Comments: in Chinese language

Secure Password Generator Based on Secure Pseudo-Random Number Generator

Authors: Abel C. H. Chen

Abstract: In recent years, numerous incidents involving the leakage of website accounts and text passwords (referred to as passwords) have raised significant concerns regarding the potential exposure of personal information. These events underscore the critical importance of both information security and password protection. While many of these breaches are attributable to vulnerabilities within website inf… ▽ More In recent years, numerous incidents involving the leakage of website accounts and text passwords (referred to as passwords) have raised significant concerns regarding the potential exposure of personal information. These events underscore the critical importance of both information security and password protection. While many of these breaches are attributable to vulnerabilities within website infrastructure, the strength and security of the passwords themselves also play a crucial role. Consequently, the creation of secure passwords constitutes a fundamental aspect of enhancing overall system security and protecting personal data. In response to these challenges, this study presents a secure password generation approach utilizing a cryptographically secure Pseudo-Random Number Generator (PRNG). The generator is implemented using a range of Message Authentication Code (MAC) algorithms, including the Keyed-Hash Message Authentication Code (HMAC), Cipher-based Message Authentication Code (CMAC), and KECCAK Message Authentication Code (KMAC), to produce robust random values suitable for password generation. To evaluate the proposed method, empirical assessments were conducted in accordance with the guidelines provided in the National Institute of Standards and Technology (NIST) Special Publication (SP) 800-90B. The evaluation focused on two primary aspects: entropy estimation and verification of independent and identically distributed (IID) properties. Experimental results indicate that the proposed method satisfies both entropy and IID requirements, thereby demonstrating its ability to generate passwords with a high degree of randomness and security. △ Less

Submitted 25 August, 2025; originally announced September 2025.

Comments: in Chinese language

NIST Post-Quantum Cryptography Standard Algorithms Based on Quantum Random Number Generators

Authors: Abel C. H. Chen

Abstract: In recent years, the advancement of quantum computing technology has posed potential security threats to RSA cryptography and elliptic curve cryptography. In response, the National Institute of Standards and Technology (NIST) published several Federal Information Processing Standards (FIPS) of post-quantum cryptography (PQC) in August 2024, including the Module-Lattice-Based Key-Encapsulation Mech… ▽ More In recent years, the advancement of quantum computing technology has posed potential security threats to RSA cryptography and elliptic curve cryptography. In response, the National Institute of Standards and Technology (NIST) published several Federal Information Processing Standards (FIPS) of post-quantum cryptography (PQC) in August 2024, including the Module-Lattice-Based Key-Encapsulation Mechanism (ML-KEM), Module-Lattice-Based Digital Signature Algorithm (ML-DSA), and Stateless Hash-Based Digital Signature Algorithm (SLH-DSA). Although these PQC algorithms are designed to resist quantum computing attacks, they may not provide adequate security in certain specialized application scenarios. To address this issue, this study proposes quantum random number generator (QRNG)-based PQC algorithms. These algorithms leverage quantum computing to generate random numbers, which serve as the foundation for key pair generation, key encapsulation, and digital signature generation. A generalized architecture of QRNG is proposed, along with the design of six QRNGs. Each generator is evaluated according to the statistical validation procedures outlined in NIST SP 800-90B, including tests for verification of entropy sources and independent and identically distributed (IID) outputs. Experimental results assess the computation time of the six QRNGs, as well as the performance of QRNG-based ML-KEM, QRNG-based ML-DSA, and QRNG-based SLH-DSA. These findings provide valuable reference data for future deployment of PQC systems. △ Less

Submitted 23 July, 2025; originally announced July 2025.

Comments: in Chinese language

Journal ref: Journal of Web Engineering ( Volume: 25, Issue: 5, July 2026)

A Comparative Study and Implementation of Key Derivation Functions Standardized by NIST and IEEE

Authors: Abel C. H. Chen

Abstract: Since many applications and services require pseudorandom numbers (PRNs), it is feasible to generate specific PRNs under given key values and input messages using Key Derivation Functions (KDFs). These KDFs are primarily constructed based on Message Authentication Codes (MACs), where the MAC serves as a core component in the generation of pseudorandom numbers. In light of this, the study first exa… ▽ More Since many applications and services require pseudorandom numbers (PRNs), it is feasible to generate specific PRNs under given key values and input messages using Key Derivation Functions (KDFs). These KDFs are primarily constructed based on Message Authentication Codes (MACs), where the MAC serves as a core component in the generation of pseudorandom numbers. In light of this, the study first examines three MAC algorithms defined by the National Institute of Standards and Technology (NIST): the Keyed-Hash Message Authentication Code (HMAC), the Cipher-based Message Authentication Code (CMAC), and the Keccak-based Message Authentication Code (KMAC). Subsequently, the study explores KDFs based on these MACs, including the Counter Mode KDF, the KMAC-based KDF, and the KDF defined in IEEE 1609.2.1. In experiments, the computation times for generating MACs and the corresponding pseudorandom numbers using each KDF are evaluated. The study further analyzes the advantages, disadvantages, and applicable scenarios for each method. Experimental results indicate that the CMAC and the CMAC-based KDF exhibit the shortest computation times, averaging approximately 0.007 milliseconds and 0.014 milliseconds, respectively. △ Less

Submitted 23 June, 2025; originally announced July 2025.

Comments: in Chinese language

HQSI: Hybrid Quantum Swarm Intelligence -- A Case Study of Online Certificate Status Protocol Request Flow Prediction

Authors: Abel C. H. Chen

Abstract: As quantum computing technology continues to advance, various sectors, including industry, government, academia, and research, have increasingly focused on its future applications. With the integration of artificial intelligence techniques, multiple Quantum Neural Network (QNN) models have been proposed, including quantum convolutional neural networks, quantum long short-term memory networks, and… ▽ More As quantum computing technology continues to advance, various sectors, including industry, government, academia, and research, have increasingly focused on its future applications. With the integration of artificial intelligence techniques, multiple Quantum Neural Network (QNN) models have been proposed, including quantum convolutional neural networks, quantum long short-term memory networks, and quantum generative adversarial networks. Furthermore, optimization methods such as constrained optimization by linear approximation and simultaneous perturbation stochastic approximation have been explored. Therefore, this study proposes Hybrid Quantum Swarm Intelligence (HQSI), which constructs a QNN model as a forward propagation neural network. After measuring quantum states and obtaining prediction results, a classical computer-based swarm intelligence algorithm is employed for weight optimization. The training process iterates between quantum and classical computing environments. During the experimental phase, the proposed HQSI method is evaluated using an online certificate status protocol request traffic prediction task. Comparative analysis against state-of-the-art quantum optimization algorithms demonstrates that the proposed HQSI approach achieves more than a 50% reduction in error. △ Less

Submitted 22 May, 2025; v1 submitted 7 May, 2025; originally announced May 2025.

Comments: in Chinese language. Remove the mistakenly included copyright notice from the article template on May 23, 2025

Implementation of Shor Algorithm: Factoring a 4096-Bit Integer Under Specific Constraints

Authors: Abel C. H. Chen

Abstract: In recent years, advancements in quantum chip technology, such as Willow, have contributed to reducing quantum computation error rates, potentially accelerating the practical adoption of quantum computing. As a result, the design of quantum algorithms suitable for real-world applications has become a crucial research direction. This study focuses on the implementation of Shor algorithm, aiming to… ▽ More In recent years, advancements in quantum chip technology, such as Willow, have contributed to reducing quantum computation error rates, potentially accelerating the practical adoption of quantum computing. As a result, the design of quantum algorithms suitable for real-world applications has become a crucial research direction. This study focuses on the implementation of Shor algorithm, aiming to improve modular computation efficiency and demonstrate the factorization of a 4096-bit integer under specific constraints. Experimental results, when compared with state-of-the-art (SOTA) methods, indicate a significant improvement in efficiency while enabling the factorization of longer integers. △ Less

Submitted 15 May, 2025; v1 submitted 6 April, 2025; originally announced May 2025.

Comments: in Chinese language; some typographical errors were corrected on May 15, 2025

Man-in-the-Middle Attacks Targeting Quantum Cryptography

Authors: Abel C. H. Chen

Abstract: The development of the Willow quantum chip by Google has sparked significant interest in quantum computing, ushering in a new wave of advancements in the field. As quantum computing technology continues to mature, secure quantum communication has garnered increasing attention. To establish secure communication, several quantum key distribution (QKD) protocols have been proposed, such as the BB84 p… ▽ More The development of the Willow quantum chip by Google has sparked significant interest in quantum computing, ushering in a new wave of advancements in the field. As quantum computing technology continues to mature, secure quantum communication has garnered increasing attention. To establish secure communication, several quantum key distribution (QKD) protocols have been proposed, such as the BB84 protocol, which leverages the principles of quantum superposition and other quantum properties to ensure secure transmission. However, existing QKD protocols may face vulnerabilities under certain conditions. This study proposes two types of man-in-the-middle (MITM) attack techniques and demonstrates their potential to compromise quantum cryptography through practical case studies. Furthermore, this study proposes strategies to counteract these MITM attacks and proposes methods to enhance the security of quantum cryptographic systems. The findings offer valuable insights for the future implementation and deployment of secure quantum communication systems. △ Less

Submitted 1 February, 2025; originally announced March 2025.

Comments: in Chinese language

One-Time Signature Based on Pseudorandom Number Generator

Authors: Abel C. H. Chen

Abstract: With the advancement of quantum computing technologies, recent years have seen increasing efforts to identify cryptographic methods resistant to quantum attacks and to establish post-quantum cryptography (PQC) approaches. Among these, hash-based digital signature algorithms (DSAs) are a notable category of PQC. Hash functions are not only utilized in digital signatures but are also widely applied… ▽ More With the advancement of quantum computing technologies, recent years have seen increasing efforts to identify cryptographic methods resistant to quantum attacks and to establish post-quantum cryptography (PQC) approaches. Among these, hash-based digital signature algorithms (DSAs) are a notable category of PQC. Hash functions are not only utilized in digital signatures but are also widely applied in pseudorandom number generators (PRNGs). Building on the foundation of hash-based DSAs, this study proposes a modified approach that introduces a DSA based on PRNGs, suitable for one-time signature (OTS) applications. The study explores the security of the proposed PRNG-based OTS algorithm and validates its feasibility through experiments comparing various parameter configurations. These experiments examine key length, signature length, key generation time, signature generation time, and signature verification time under different parameter settings. △ Less

Submitted 23 December, 2024; originally announced January 2025.

Comments: in Chinese language

Hybrid Scheme of Post-Quantum Cryptography and Elliptic-Curve Cryptography for Certificates -- A Case Study of Security Credential Management System in Vehicle-to-Everything Communications

Authors: Abel C. H. Chen, Bon-Yeh Lin

Abstract: Due to the current standard of Security Credential Management System (SCMS) for Vehicle-to-Everything (V2X) communications using asymmetric cryptography, specifically Elliptic-Curve Cryptography (ECC), which may be vulnerable to quantum computing attacks. Therefore, the V2X SCMS is threatened by quantum computing attacks. However, although the National Institute of Standards and Technology (NIST)… ▽ More Due to the current standard of Security Credential Management System (SCMS) for Vehicle-to-Everything (V2X) communications using asymmetric cryptography, specifically Elliptic-Curve Cryptography (ECC), which may be vulnerable to quantum computing attacks. Therefore, the V2X SCMS is threatened by quantum computing attacks. However, although the National Institute of Standards and Technology (NIST) has already selected Post-Quantum Cryptography (PQC) algorithms as the standard, the current PQC algorithms may have issues such as longer public key lengths, longer signature lengths, or lower signature generation and verification efficiency, which may not fully meet the requirements of V2X communication applications. In view of the challenges in V2X communication, such as packet length, signature generation and verification efficiency, security level, and vehicle privacy, this study proposes a hybrid certificate scheme of PQC and ECC. By leveraging the strengths of both PQC and ECC, this scheme aims to overcome the challenges in V2X communication. PQC is used to establish a security level resistant to quantum computing attacks, while ECC is utilized to establish anonymous certificates and reduce packet length to meet the requirements of V2X communication. In the practical experiments, the study implemented the SCMS end entity based on the Chunghwa Telecom SCMS and the Clientron On-Board Unit (OBU) to conduct field tests in Danhai New Town in New Taipei City. The performance of various existing hybrid certificate schemes combining PQC (e.g., Dilithium, Falcon, and SPHINCS+) and ECC is compared, and a practical solution is provided for V2X industries. △ Less

Submitted 12 January, 2025; originally announced January 2025.

Comments: The manuscript is written in Chinese language

An Efficient Key Expansion Method Applied to Security Credential Management System

Authors: Abel C. H. Chen

Abstract: In recent years, U.S. Department of Transportation has adopts Institute of Electrical and Electronics Engineers (IEEE) 1609 series to build the security credential management system (SCMS) for being the standard of connected cars in U.S. Furthermore, a butterfly key expansion (BKE) method in SCMS has been designed to provide pseudonym certificates for improving the privacy of connected cars. Howev… ▽ More In recent years, U.S. Department of Transportation has adopts Institute of Electrical and Electronics Engineers (IEEE) 1609 series to build the security credential management system (SCMS) for being the standard of connected cars in U.S. Furthermore, a butterfly key expansion (BKE) method in SCMS has been designed to provide pseudonym certificates for improving the privacy of connected cars. However, the BKE method is designed based on elliptic curve cryptography (ECC) in the standard of IEEE 1609.2.1, but more execution time is required for key expansion. Therefore, this study proposes an original efficient key expansion method, and the mathematical principles have been proposed to prove the encryption/decryption feasibility, car privacy, and method efficiency. In a practical environment, the proposed method improves the efficiency of key expansion method in IEEE 1609.2.1-2022 with the same security strength thousands of times. △ Less

Submitted 9 January, 2025; originally announced January 2025.

Comments: The manuscript was submitted to arXiv on 27 November 2023, but it was rejected on 2 December 2023. The appeal was submitted on 18 September 2024, and it was accepted on 9 January 2025. The manuscript is written in Chinese language

Homomorphic Encryption Based on Lattice Post-Quantum Cryptography

Authors: Abel C. H. Chen

Abstract: As quantum computing technology continues to advance, post-quantum cryptographic methods capable of resisting quantum attacks have emerged as a critical area of focus. Given the potential vulnerability of existing homomorphic encryption methods, such as RSA, ElGamal, and Paillier, to quantum computing attacks, this study proposes a lattice-based post-quantum homomorphic encryption scheme. The appr… ▽ More As quantum computing technology continues to advance, post-quantum cryptographic methods capable of resisting quantum attacks have emerged as a critical area of focus. Given the potential vulnerability of existing homomorphic encryption methods, such as RSA, ElGamal, and Paillier, to quantum computing attacks, this study proposes a lattice-based post-quantum homomorphic encryption scheme. The approach leverages lattice cryptography to build resilience against quantum threats while enabling practical homomorphic encryption applications. This research provides mathematical proofs and computational examples, alongside a security analysis of the lattice-based post-quantum homomorphic encryption scheme. The findings are intended to serve as a reference for developers of homomorphic encryption applications, such as federated learning systems. △ Less

Submitted 23 December, 2024; originally announced January 2025.

Comments: in Chinese language

Performance Comparison of Security Credential Management Systems for V2X: North American Standard IEEE 1609.2.1 and European Standard ETSI TS 102 941

Authors: Abel C. H. Chen

Abstract: This study examines the performance and structural differences between the two primary standards for Security Credential Management Systems (SCMS) in Vehicular-to-Everything (V2X) communication: the North American IEEE standards and the European ETSI standards. It focuses on comparing their respective Public Key Infrastructure (PKI) architectures, certificate application workflows, and the formats… ▽ More This study examines the performance and structural differences between the two primary standards for Security Credential Management Systems (SCMS) in Vehicular-to-Everything (V2X) communication: the North American IEEE standards and the European ETSI standards. It focuses on comparing their respective Public Key Infrastructure (PKI) architectures, certificate application workflows, and the formats of request/response messages used during certificate applications. The research includes a theoretical analysis of message length and security features inherent in each standard. Additionally, practical implementations of both systems are conducted to evaluate their efficiency in certificate management processes. Based on the findings, the study provides recommendations to guide future development of SCMS. △ Less

Submitted 16 December, 2024; originally announced January 2025.

Comments: in Chinese language

EQNN: Enhanced Quantum Neural Network

Authors: Abel C. H. Chen

Abstract: With the maturation of quantum computing technology, research has gradually shifted towards exploring its applications. Alongside the rise of artificial intelligence, various machine learning methods have been developed into quantum circuits and algorithms. Among them, Quantum Neural Networks (QNNs) can map inputs to quantum circuits through Feature Maps (FMs) and adjust parameter values via varia… ▽ More With the maturation of quantum computing technology, research has gradually shifted towards exploring its applications. Alongside the rise of artificial intelligence, various machine learning methods have been developed into quantum circuits and algorithms. Among them, Quantum Neural Networks (QNNs) can map inputs to quantum circuits through Feature Maps (FMs) and adjust parameter values via variational models, making them applicable in regression and classification tasks. However, designing a FM that is suitable for a given application problem is a significant challenge. In light of this, this study proposes an Enhanced Quantum Neural Network (EQNN), which includes an Enhanced Feature Map (EFM) designed in this research. This EFM effectively maps input variables to a value range more suitable for quantum computing, serving as the input to the variational model to improve accuracy. In the experimental environment, this study uses mobile data usage prediction as a case study, recommending appropriate rate plans based on users' mobile data usage. The proposed EQNN is compared with current mainstream QNNs, and experimental results show that the EQNN achieves higher accuracy with fewer quantum logic gates and converges to the optimal solution faster under different optimization algorithms. △ Less

Submitted 28 November, 2024; v1 submitted 21 November, 2024; originally announced November 2024.

Comments: in Chinese language

Key Expansion Based on Internet X.509 Public Key Infrastructure for Anonymous Voting

Authors: Abel C. H. Chen

Abstract: This document focuses on developing a key expansion method based on the internet X.509 public key infrastructure and elliptic curve cryptography, which is applied in the context of anonymous voting. The method enables end entities to maintain anonymity from other end entities, the registration authority, and the certificate authority, while still allowing the validity of end entity certificates to… ▽ More This document focuses on developing a key expansion method based on the internet X.509 public key infrastructure and elliptic curve cryptography, which is applied in the context of anonymous voting. The method enables end entities to maintain anonymity from other end entities, the registration authority, and the certificate authority, while still allowing the validity of end entity certificates to be verified, thereby facilitating anonymous voting services. △ Less

Submitted 7 October, 2024; originally announced October 2024.

Comments: This document has been made available as a draft on the IETF website (https://datatracker.ietf.org/doc/draft-chen-x509-anonymous-voting/)

Post-Quantum Cryptography Anonymous Scheme -- PQCWC: Post-Quantum Cryptography Winternitz-Chen

Authors: Abel C. H. Chen

Abstract: As quantum computing technology matures, it poses a threat to the security of mainstream asymmetric cryptographic methods. In response, the National Institute of Standards and Technology released the final version of post-quantum cryptographic (PQC) algorithm standards in August 2024. These post-quantum cryptographic algorithms are primarily based on lattice-based and hash-based cryptography. Ther… ▽ More As quantum computing technology matures, it poses a threat to the security of mainstream asymmetric cryptographic methods. In response, the National Institute of Standards and Technology released the final version of post-quantum cryptographic (PQC) algorithm standards in August 2024. These post-quantum cryptographic algorithms are primarily based on lattice-based and hash-based cryptography. Therefore, this study proposes the Post-Quantum Cryptography Winternitz-Chen (PQCWC) anonymous scheme, aimed at exploring the design of anonymous schemes based on PQC for future applications in privacy protection. The anonymous scheme designed in this study is mainly built on the Winternitz signature scheme, which can prevent the original public key from being exposed in the certificate. Furthermore, the PQCWC anonymous scheme integrates the butterfly key expansion mechanism, proposing the first hash-based butterfly key expansion mechanism in the world, achieving anonymity for both the registration authority and the certificate authority, thereby fully protecting privacy. In the experimental environment, this study compares various hash algorithms, including Secure Hash Algorithm-1 (SHA-1), the SHA-2 series, the SHA-3 series, and the BLAKE series. The results demonstrate that the proposed anonymous scheme can achieve anonymity without increasing key length, signature length, key generation time, signature generation time, or signature verification time. △ Less

Submitted 19 September, 2024; originally announced October 2024.

Comments: in Chinese language

Evaluation of Hash Algorithm Performance for Cryptocurrency Exchanges Based on Blockchain System

Authors: Abel C. H. Chen

Abstract: The blockchain system has emerged as one of the focal points of research in recent years, particularly in applications and services such as cryptocurrencies and smart contracts. In this context, the hash value serves as a crucial element in linking blocks within the blockchain, ensuring the integrity of block contents. Therefore, hash algorithms represent a vital security technology for ensuring t… ▽ More The blockchain system has emerged as one of the focal points of research in recent years, particularly in applications and services such as cryptocurrencies and smart contracts. In this context, the hash value serves as a crucial element in linking blocks within the blockchain, ensuring the integrity of block contents. Therefore, hash algorithms represent a vital security technology for ensuring the integrity and security of blockchain systems. This study primarily focuses on analyzing the security and execution efficiency of mainstream hash algorithms in the Proof of Work (PoW) calculations within blockchain systems. It proposes an evaluation factor and conducts comparative experiments to evaluate each hash algorithm. The experimental results indicate that there are no significant differences in the security aspects among SHA-2, SHA-3, and BLAKE2. However, SHA-2 and BLAKE2 demonstrate shorter computation times, indicating higher efficiency in execution. △ Less

Submitted 8 August, 2024; originally announced August 2024.

X.509 Information Security Certification Based on Post-Quantum Cryptography

Authors: Abel C. H. Chen

Abstract: In recent years, with the advancement of quantum computing, mainstream asymmetric cryptographic methods in the current Public Key Infrastructure (PKI) systems are gradually being threatened. Therefore, this study explores X.509 security certificates based on Post-Quantum Cryptography (PQC) and discusses implemented solutions. This study compares mainstream asymmetric cryptographic methods (includi… ▽ More In recent years, with the advancement of quantum computing, mainstream asymmetric cryptographic methods in the current Public Key Infrastructure (PKI) systems are gradually being threatened. Therefore, this study explores X.509 security certificates based on Post-Quantum Cryptography (PQC) and discusses implemented solutions. This study compares mainstream asymmetric cryptographic methods (including RSA and Elliptic Curve Digital Signature Algorithm (ECDSA)) with standard PQC methods (including Falcon, Dilithium, SPHINCS+), comparing the efficiency of certificate generation, signature generation, and signature verification. Finally, recommendations for a solution based on PQC for X.509 security certificates are proposed. △ Less

Submitted 4 August, 2024; originally announced August 2024.

Comments: The manuscript was submitted to arXiv on 6 May 2024, but it was rejected on 11 July 2024. The appeal was submitted on 11 July 2024, and it was accepted on 2 August 2024. The manuscript is written in Chinese language

A Study on the Situation of Connected Car Patent Portfolios

Authors: Abel C. H. Chen, Chia-Shen Chang

Abstract: In recent years, the countries of the world have drafted the specifications of connected cars; for instance, the Security Credential Management System (SCMS) has been proposed by United States Department of Transportation (USDOT), and the Cooperative Intelligent Transportation System (C-ITS) Credential Management System (CCMS) has been proposed by European Union (EU). Therefore, several companies… ▽ More In recent years, the countries of the world have drafted the specifications of connected cars; for instance, the Security Credential Management System (SCMS) has been proposed by United States Department of Transportation (USDOT), and the Cooperative Intelligent Transportation System (C-ITS) Credential Management System (CCMS) has been proposed by European Union (EU). Therefore, several companies have developed the technology and productions of connected cars based on specifications, and connected car patent portfolios have been proactively performed. Therefore, this study uses Patent Search System (PSS) to find and analyze the contents of patents for obtaining the innovation reports of connected cars according to patents. This study considers the single-factor and two-factors to analyze the relationships of annuals, major technology leaders, major market leaders, and major technology and applications for exploring the patent portfolios of technology leaders and market leaders in connected cars. △ Less

Submitted 26 June, 2024; originally announced July 2024.

Comments: in Chinese language

Performance Comparison of Various Modes of Advanced Encryption Standard

Authors: Abel C. H. Chen

Abstract: With the maturation of quantum computing technology, many cryptographic methods are gradually facing threats from quantum computing. Although the Grover algorithm can accelerate search speeds, current research indicates that the Advanced Encryption Standard (AES) method can still enhance security by increasing the length of the secret key. However, the AES method involves multiple modes in impleme… ▽ More With the maturation of quantum computing technology, many cryptographic methods are gradually facing threats from quantum computing. Although the Grover algorithm can accelerate search speeds, current research indicates that the Advanced Encryption Standard (AES) method can still enhance security by increasing the length of the secret key. However, the AES method involves multiple modes in implementation, and not all modes are secure. Therefore, this study proposes a normalized Gini impurity (NGI) to verify the security of each mode, using encrypted images as a case study for empirical analysis. Furthermore, this study primarily compares the Electronic Codebook (ECB) mode, Cipher Block Chaining (CBC) mode, Counter (CTR) mode, Counter with CBC-Message Authentication Code (MAC) (CCM) mode, and Galois Counter Mode (GCM). △ Less

Submitted 21 May, 2024; originally announced July 2024.

Comments: in Chinese language

The Security Performance Analysis of Blockchain System Based on Post-Quantum Cryptography -- A Case Study of Cryptocurrency Exchanges

Authors: Abel C. H. Chen

Abstract: The current blockchain system for cryptocurrency exchanges primarily employs elliptic curve cryptography (ECC) for generating key pairs in wallets, and elliptic curve digital signature algorithms (ECDSA) for generating signatures in transactions. Consequently, with the maturation of quantum computing technology, the current blockchain system faces the risk of quantum computing attacks. Quantum com… ▽ More The current blockchain system for cryptocurrency exchanges primarily employs elliptic curve cryptography (ECC) for generating key pairs in wallets, and elliptic curve digital signature algorithms (ECDSA) for generating signatures in transactions. Consequently, with the maturation of quantum computing technology, the current blockchain system faces the risk of quantum computing attacks. Quantum computers may potentially counterfeit signatures produced by ECDSA. Therefore, this study analyzes the vulnerabilities of the current blockchain system to quantum computing attacks and proposes a post-quantum cryptography (PQC)-based blockchain system to enhance security by addressing and improving each identified weakness. Furthermore, this study proposes PQC-based wallets and PQC-based transactions, utilizing PQC digital signature algorithms to generate PQC-based signatures for the inputs in PQC-based transactions, thereby preventing signatures from being counterfeited by quantum computing. Experimental results demonstrate that the efficiency of the Dilithium algorithm, a PQC digital signature algorithm, in producing wallets, generating signatures, and verifying signatures surpasses that of ECDSA in the current blockchain system. Furthermore, the Dilithium algorithm also exhibits a higher security level. △ Less

Submitted 23 January, 2024; originally announced April 2024.

Comments: in Chinese language

Post-Quantum Cryptography Neural Network

Authors: Abel C. H. Chen

Abstract: In recent years, quantum computers and Shor quantum algorithm have posed a threat to current mainstream asymmetric cryptography methods (e.g. RSA and Elliptic Curve Cryptography (ECC)). Therefore, it is necessary to construct a Post-Quantum Cryptography (PQC) method to resist quantum computing attacks. Therefore, this study proposes a PQC-based neural network that maps a code-based PQC method to a… ▽ More In recent years, quantum computers and Shor quantum algorithm have posed a threat to current mainstream asymmetric cryptography methods (e.g. RSA and Elliptic Curve Cryptography (ECC)). Therefore, it is necessary to construct a Post-Quantum Cryptography (PQC) method to resist quantum computing attacks. Therefore, this study proposes a PQC-based neural network that maps a code-based PQC method to a neural network structure and enhances the security of ciphertexts with non-linear activation functions, random perturbation of ciphertexts, and uniform distribution of ciphertexts. In practical experiments, this study uses cellular network signals as a case study to demonstrate that encryption and decryption can be performed by the proposed PQC-based neural network with the uniform distribution of ciphertexts. In the future, the proposed PQC-based neural network could be applied to various applications. △ Less

Submitted 25 February, 2024; originally announced February 2024.

Comments: 2023 International Conference on Smart Systems for applications in Electrical Sciences (ICSSES) 7-8 July 2023. The manuscript was written in Chinese and submitted on 10 March 2023, but it was rejected on 22 April 2023. The appeal was accepted on 24 February 2024

Homomorphic Encryption Based on Post-Quantum Cryptography

Authors: Abel C. H. Chen

Abstract: With the development of Shor's algorithm, some nondeterministic polynomial (NP) time problems (e.g. prime factorization problems and discrete logarithm problems) may be solved in polynomial time. In recent years, although some homomorphic encryption algorithms have been proposed based on prime factorization problems, the algorithms may be cracked by quantum computing attacks. Therefore, this study… ▽ More With the development of Shor's algorithm, some nondeterministic polynomial (NP) time problems (e.g. prime factorization problems and discrete logarithm problems) may be solved in polynomial time. In recent years, although some homomorphic encryption algorithms have been proposed based on prime factorization problems, the algorithms may be cracked by quantum computing attacks. Therefore, this study proposes a post-quantum cryptography (PQC)-based homomorphic encryption method which includes the homomorphic encryption function based on a code-based cryptography method for avoiding quantum computing attacks. Subsection 3.2 proposes mathematical models to prove the feasibility of the proposed method, and Subsection 3.3 gives calculation examples to present the detailed steps of the proposed method. In experimental environments, the mainstream cryptography methods (i.e. RSA cryptography and elliptic curve cryptography (ECC)) have been compared, and the results show that the encryption time and decryption time of the proposed method are shorter than other cryptography methods. Furthermore, the proposed method is designed based on a non-negative matrix factorization problem (i.e. a NP problem) for resisting quantum computing attacks. △ Less

Submitted 21 February, 2024; originally announced February 2024.

PQCMC: Post-Quantum Cryptography McEliece-Chen Implicit Certificate Scheme

Authors: Abel C. H. Chen

Abstract: In recent years, the elliptic curve Qu-Vanstone (ECQV) implicit certificate scheme has found application in security credential management systems (SCMS) and secure vehicle-to-everything (V2X) communication to issue pseudonymous certificates. However, the vulnerability of elliptic-curve cryptography (ECC) to polynomial-time attacks posed by quantum computing raises concerns. In order to enhance re… ▽ More In recent years, the elliptic curve Qu-Vanstone (ECQV) implicit certificate scheme has found application in security credential management systems (SCMS) and secure vehicle-to-everything (V2X) communication to issue pseudonymous certificates. However, the vulnerability of elliptic-curve cryptography (ECC) to polynomial-time attacks posed by quantum computing raises concerns. In order to enhance resistance against quantum computing threats, various post-quantum cryptography methods have been adopted as standard (e.g. Dilithium) or candidate standard methods (e.g. McEliece cryptography), but state of the art has proven to be challenging to implement implicit certificates using lattice-based cryptography methods. Therefore, this study proposes a post-quantum cryptography McEliece-Chen (PQCMC) based on an efficient random invertible matrix generation method to issue pseudonymous certificates with less computation time. The study provides mathematical models to validate the key expansion process for implicit certificates. Furthermore, comprehensive security evaluations and discussions are conducted to demonstrate that distinct implicit certificates can be linked to the same end entity. In experiments, a comparison is conducted between the certificate length and computation time to evaluate the performance of the proposed PQCMC. This study demonstrates the viability of the implicit certificate scheme based on PQC as a means of countering quantum computing threats. △ Less

Submitted 3 January, 2024; originally announced January 2024.

Performance Analysis of Security Certificate Management System in Vehicle-to-Everything (V2X)

Authors: Abel C. H. Chen, Cheng-Kang Liu, Chun-Feng Lin, Bon-Yeh Lin

Abstract: In Vehicle-to-Everything (V2X) communications, providing accurate information and safeguarding the privacy of end entities is one of the crucial information security issues. Therefore, several international standardization organizations have begun to develop V2X communication security standards in recent years. For instance, the IEEE 1609.2.1 standard designs a Security Credential Management Syste… ▽ More In Vehicle-to-Everything (V2X) communications, providing accurate information and safeguarding the privacy of end entities is one of the crucial information security issues. Therefore, several international standardization organizations have begun to develop V2X communication security standards in recent years. For instance, the IEEE 1609.2.1 standard designs a Security Credential Management System (SCMS) that specifies certificate application and issuance processes, as well as certificate revocation processes. Furthermore, the IEEE 1609.2 standard defines certificate formats and Secure Protocol Data Units (SPDUs) for secure data transmission based on these standards. As a result, end entity manufacturers and SCMS providers worldwide have started building V2X security systems in accordance with these standards and conducting interoperability testing. Although international standards mainly employ Elliptic-Curve Cryptography (ECC) for signature/verification and encryption/decryption functions, performance analysis remains a crucial issue for the practical deployment of these systems. Therefore, this study implements end entities and a SCMS conforming to IEEE 1609.2 and IEEE 1609.2.1 standards. It measures the computation and transmission times for each security communication action within the system from the perspective of end entities and identifies potential system bottlenecks. In the experimental results, this study analyzes the most performance-intensive actions and provides relevant suggestions for enhancing system efficiency for SCMS developers to reference. △ Less

Submitted 17 September, 2023; originally announced November 2023.

Comments: in Chinese language

Evaluation and Analysis of Standard Security Technology in V2X Communication -- Exploring ECQV Implicit Certificate Cracking

Authors: Abel C. H. Chen

Abstract: In IEEE 1609.2 and IEEE 1609.2.1 standards for Vehicle-to-everything (V2X) secure communication, various security algorithms based on Elliptic Curve Cryptography (ECC) have been adopted and designed. To enhance the efficiency of the Security Credential Management System (SCMS), this study evaluates the computational time for key generation, key expansion, signature generation, and signature verifi… ▽ More In IEEE 1609.2 and IEEE 1609.2.1 standards for Vehicle-to-everything (V2X) secure communication, various security algorithms based on Elliptic Curve Cryptography (ECC) have been adopted and designed. To enhance the efficiency of the Security Credential Management System (SCMS), this study evaluates the computational time for key generation, key expansion, signature generation, and signature verification under different security strengths. This study discusses relevant techniques based on Elliptic Curve Qu-Vanstone (ECQV) implicit certificates, analyzes the length of uncompressed elliptic curve points, compressed elliptic curve points, explicit certificates, and implicit certificates. Furthermore, this study proposes mathematical models to demonstrate the probability of ECQV cracking and provides suggestions for mitigating ECQV cracking risks. △ Less

Submitted 26 September, 2023; originally announced September 2023.

Comments: in Chinese language

The Pseudonymous Certificates for Healthcare Systems

Authors: Abel C. H. Chen

Abstract: This study mainly modifies the butterfly key expansion (BKE) mechanism and applies it to the healthcare system. The system mainly includes a Root Certificate Authority (RCA), an Enrollment Certificate Authority (ECA), a Pseudonym Certificate Authority (PCA), a Registration Authority (RA), and End Entities (EEs)(i.e. user devices). Certificates can be issued by the RCA to the ECA, PCA, and RA to ma… ▽ More This study mainly modifies the butterfly key expansion (BKE) mechanism and applies it to the healthcare system. The system mainly includes a Root Certificate Authority (RCA), an Enrollment Certificate Authority (ECA), a Pseudonym Certificate Authority (PCA), a Registration Authority (RA), and End Entities (EEs)(i.e. user devices). Certificates can be issued by the RCA to the ECA, PCA, and RA to make them legal entities in the system. The ECA then issues device certificates (similar to identification cards for devices) to the EEs (e.g. blood pressure monitors). When patients use EEs to measure physiological information, the RA verifies that the EE is legal based on the issued multiple pseudonym certificates by the PCA. The EE then uses the pseudonym certificates to send physiological information to the RA, ensuring data integrity and non-repudiation, while also preventing identity information from being stolen. To verify the pseudonymous certificate-based healthcare system proposed in this study, the security of the system was verified using the security strengths defined by the National Institute of Standards and Technology (NIST) in the United States. Furthermore, as the BKE mechanism is primarily based on Elliptic Curve Cryptography (ECC), this study also verified the efficiency under different security strengths. Furthermore, under 256 of security strength, the mean computation time of key expansion is between 24186.584 microseconds and 57894.552 microseconds, so more than 18 public keys could be generated in one second. △ Less

Submitted 23 April, 2023; originally announced July 2023.

Comments: in Chinese language

Research on Efficiency Analysis of Microservices

Authors: Abel C. H. Chen

Abstract: With the maturity of web services, containers, and cloud computing technologies, large services in traditional systems (e.g. the computation services of machine learning and artificial intelligence) are gradually being broken down into many microservices to increase service reusability and flexibility. Therefore, this study proposes an efficiency analysis framework based on queuing models to analy… ▽ More With the maturity of web services, containers, and cloud computing technologies, large services in traditional systems (e.g. the computation services of machine learning and artificial intelligence) are gradually being broken down into many microservices to increase service reusability and flexibility. Therefore, this study proposes an efficiency analysis framework based on queuing models to analyze the efficiency difference of breaking down traditional large services into n microservices. For generalization, this study considers different service time distributions (e.g. exponential distribution of service time and fixed service time) and explores the system efficiency in the worst-case and best-case scenarios through queuing models (i.e. M/M/1 queuing model and M/D/1 queuing model). In each experiment, it was shown that the total time required for the original large service was higher than that required for breaking it down into multiple microservices, so breaking it down into multiple microservices can improve system efficiency. It can also be observed that in the best-case scenario, the improvement effect becomes more significant with an increase in arrival rate. However, in the worst-case scenario, only slight improvement was achieved. This study found that breaking down into multiple microservices can effectively improve system efficiency and proved that when the computation time of the large service is evenly distributed among multiple microservices, the best improvement effect can be achieved. Therefore, this study's findings can serve as a reference guide for future development of microservice architecture. △ Less

Submitted 20 March, 2023; originally announced March 2023.

Comments: in Chinese language

Similarity Calculation Based on Homomorphic Encryption

Authors: Abel C. H. Chen

Abstract: In recent years, although some homomorphic encryption algorithms have been proposed to provide additive homomorphic encryption and multiplicative homomorphic encryption. However, similarity measures are required for searches and queries under homomorphic encrypted ciphertexts. Therefore, this study considers the cosine similarity, angular similarity, Tanimoto similarity, and soft cosine similarity… ▽ More In recent years, although some homomorphic encryption algorithms have been proposed to provide additive homomorphic encryption and multiplicative homomorphic encryption. However, similarity measures are required for searches and queries under homomorphic encrypted ciphertexts. Therefore, this study considers the cosine similarity, angular similarity, Tanimoto similarity, and soft cosine similarity and combines homomorphic encryption algorithms for similarity calculation. This study proposes mathematical models to prove the proposed homomorphic encryption-based similarity calculation methods and gives practical cases to explain the proposed methods. In experiments, the performance of the proposed homomorphic encryption-based similarity calculation methods has been evaluated under different security strengths. △ Less

Submitted 17 February, 2023; v1 submitted 15 February, 2023; originally announced February 2023.

Comments: in Chinese language

Exploring the Techniques of Information Security Certification

Authors: Abel C. H. Chen

Abstract: If the information system is intruded or attacked by hackers, leaked personal data or serious economic loss may occur; the threats may be serious security problems. For security services, information security certification is built based on Public Key Infrastructure (PKI) to be an important tool for the services of bank transactions, natural person certificate, blockchain, and Hyper Text Transfer… ▽ More If the information system is intruded or attacked by hackers, leaked personal data or serious economic loss may occur; the threats may be serious security problems. For security services, information security certification is built based on Public Key Infrastructure (PKI) to be an important tool for the services of bank transactions, natural person certificate, blockchain, and Hyper Text Transfer Protocol Secure (HTTPS). Therefore, this study uses Taiwan Patent Search System (TPSS) to find and analyze the contents of patents for obtaining the innovation reports of information security certification in Taiwan according to patents. This study considers the single-factor and two-factors to analyze the relationships of annuals, technology leaders, market leaders, and major applications for exploring the patent portfolios of technology leaders and market leaders in information security certification. △ Less

Submitted 14 February, 2023; originally announced February 2023.

Comments: in Chinese language

Journal ref: Journal of Informatics and Electronics, vol. 11, no. 1, pp. 135-148, 2023, URL: https://www.airitilibrary.com/Article/Detail/P20230213001-N202307210007-00008

Homomorphic Hashing Based on Elliptic Curve Cryptography

Authors: Abel C. H. Chen

Abstract: For avoiding the exposure of plaintexts in cloud environments, some homomorphic hashing algorithms have been proposed to generate the hash value of each plaintext, and cloud environments only store the hash values and calculate the hash values for future needs. However, longer hash value generation time and longer hash value summary time may be required by these homomorphic hashing algorithms with… ▽ More For avoiding the exposure of plaintexts in cloud environments, some homomorphic hashing algorithms have been proposed to generate the hash value of each plaintext, and cloud environments only store the hash values and calculate the hash values for future needs. However, longer hash value generation time and longer hash value summary time may be required by these homomorphic hashing algorithms with higher security strengths. Therefore, this study proposes a homomorphic hashing based on elliptic curve cryptography (ECC) to provide a homomorphic hashing function in accordance with the characteristics of ECC. Furthermore, mathematical models and practical cases have been given to prove the proposed method. In experiments, the results show that the proposed method have higher efficiency with different security strengths. △ Less

Submitted 15 February, 2023; v1 submitted 7 February, 2023; originally announced February 2023.

Comments: in Chinese language

How to Prove the Optimized Values of Hyperparameters for Particle Swarm Optimization?

Authors: Abel C. H. Chen

Abstract: In recent years, several swarm intelligence optimization algorithms have been proposed to be applied for solving a variety of optimization problems. However, the values of several hyperparameters should be determined. For instance, although Particle Swarm Optimization (PSO) has been applied for several applications with higher optimization performance, the weights of inertial velocity, the particl… ▽ More In recent years, several swarm intelligence optimization algorithms have been proposed to be applied for solving a variety of optimization problems. However, the values of several hyperparameters should be determined. For instance, although Particle Swarm Optimization (PSO) has been applied for several applications with higher optimization performance, the weights of inertial velocity, the particle's best known position and the swarm's best known position should be determined. Therefore, this study proposes an analytic framework to analyze the optimized average-fitness-function-value (AFFV) based on mathematical models for a variety of fitness functions. Furthermore, the optimized hyperparameter values could be determined with a lower AFFV for minimum cases. Experimental results show that the hyperparameter values from the proposed method can obtain higher efficiency convergences and lower AFFVs. △ Less

Submitted 31 January, 2023; originally announced February 2023.

Comments: in Chinese language

Exploring the Optimized Value of Each Hyperparameter in Various Gradient Descent Algorithms

Authors: Abel C. H. Chen

Abstract: In the recent years, various gradient descent algorithms including the methods of gradient descent, gradient descent with momentum, adaptive gradient (AdaGrad), root-mean-square propagation (RMSProp) and adaptive moment estimation (Adam) have been applied to the parameter optimization of several deep learning models with higher accuracies or lower errors. These optimization algorithms may need to… ▽ More In the recent years, various gradient descent algorithms including the methods of gradient descent, gradient descent with momentum, adaptive gradient (AdaGrad), root-mean-square propagation (RMSProp) and adaptive moment estimation (Adam) have been applied to the parameter optimization of several deep learning models with higher accuracies or lower errors. These optimization algorithms may need to set the values of several hyperparameters which include a learning rate, momentum coefficients, etc. Furthermore, the convergence speed and solution accuracy may be influenced by the values of hyperparameters. Therefore, this study proposes an analytical framework to use mathematical models for analyzing the mean error of each objective function based on various gradient descent algorithms. Moreover, the suitable value of each hyperparameter could be determined by minimizing the mean error. The principles of hyperparameter value setting have been generalized based on analysis results for model optimization. The experimental results show that higher efficiency convergences and lower errors can be obtained by the proposed method. △ Less

Submitted 27 December, 2022; v1 submitted 23 December, 2022; originally announced December 2022.

Comments: in Chinese language