Journal Description
Cryptography
Cryptography
is an international, scientific, peer-reviewed, open access journal on cryptography published quarterly online by MDPI.
- Open Access— free for readers, with article processing charges (APC) paid by authors or their institutions.
- High Visibility: indexed within Scopus, ESCI (Web of Science), dblp, and other databases.
- Journal Rank: JCR - Q2 (Computer Science, Theory and Methods) / CiteScore - Q1 (Applied Mathematics)
- Rapid Publication: manuscripts are peer-reviewed and a first decision is provided to authors approximately 26.9 days after submission; acceptance to publication is undertaken in 4.3 days (median values for papers published in this journal in the second half of 2024).
- Recognition of Reviewers: reviewers who provide timely, thorough peer-review reports receive vouchers entitling them to a discount on the APC of their next publication in any MDPI journal, in appreciation of the work done.
Impact Factor:
1.8 (2023);
5-Year Impact Factor:
2.1 (2023)
Latest Articles
Lightweight Scheme for Secure Signaling and Data Exchanges in Intelligent Precision Agriculture
Cryptography 2025, 9(1), 7; https://doi.org/10.3390/cryptography9010007 - 17 Jan 2025
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Intelligent precision agriculture incorporates a number of Internet of Things (IoT) devices and drones to supervise agricultural activities and surroundings. The collected data are then forwarded to processing centers to facilitate crucial decisions. This can potentially help optimize the usage of agricultural resources
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Intelligent precision agriculture incorporates a number of Internet of Things (IoT) devices and drones to supervise agricultural activities and surroundings. The collected data are then forwarded to processing centers to facilitate crucial decisions. This can potentially help optimize the usage of agricultural resources and thwart disasters, enhancing productivity and profitability. To facilitate monitoring and decision, the smart devices in precision agriculture must exchange massive amounts of data across the open wireless communication channels. This inadvertently introduces a number of vulnerabilities, exposing the collected data to numerous security and privacy threats. To address these issues, massive security solutions have been introduced to secure the communication process in precision agriculture. However, most of the current security solutions either fail to offer perfect protection or are inefficient. In this paper, a scheme deploying efficient cryptographic primitives such as hashing, exclusive OR and random number generators is presented. We utilize the Burrows–Abadi–Needham (BAN) logic to demonstrate the verifiable security of the negotiated session keys. In addition, we execute an extensive semantic analysis which reveals the robustness of our scheme against a myriad of threats. Moreover, comparative performance evaluations demonstrate its computation overheads and energy consumption efficiency.
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Open AccessArticle
Protecting Dynamically Obfuscated Scan Chain Architecture from DOSCrack with Trivium Pseudo-Random Number Generation
by
Jiaming Wu, Olivia Dizon-Paradis, Sazadur Rahman, Damon L. Woodard and Domenic Forte
Cryptography 2025, 9(1), 6; https://doi.org/10.3390/cryptography9010006 - 14 Jan 2025
Abstract
Design-for-test/debug (DfT/D) introduces scan chain testing to increase testability and fault coverage by inserting scan flip-flops. However, these scan chains are also known to be a liability for security primitives. In previous research, the dynamically obfuscated scan chain (DOSC) was introduced to protect
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Design-for-test/debug (DfT/D) introduces scan chain testing to increase testability and fault coverage by inserting scan flip-flops. However, these scan chains are also known to be a liability for security primitives. In previous research, the dynamically obfuscated scan chain (DOSC) was introduced to protect logic-locking keys from scan-based attacks by obscuring test patterns and responses. In this paper, we present DOSCrack, an oracle-guided attack to de-obfuscate DOSC using symbolic execution and binary clustering, which significantly reduces the candidate seed space to a manageable quantity. Our symbolic execution engine employs scan mode simulation and satisfiability modulo theories (SMT) solvers to reduce the possible seed space, while obfuscation key clustering allows us to effectively rule out a group of seeds that share similarities. An integral component of our approach is the use of sequential equivalence checking (SEC), which aids in identifying distinct simulation patterns to differentiate between potential obfuscation keys. We experimentally applied our DOSCrack framework on four different sizes of DOSC benchmarks and compared their runtime and complexity. Finally, we propose a low-cost countermeasure to DOSCrack which incorporates a nonlinear feedback shift register (NLFSR) to increase the effort of symbolic execution modeling and serves as an effective defense against our DOSCrack framework. Our research effectively addresses a critical vulnerability in scan-chain obfuscation methodologies, offering insights into DfT/D and logic locking for both academic research and industrial applications. Our framework highlights the need to craft robust and adaptable defense mechanisms to counter evolving scan-based attacks.
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(This article belongs to the Special Issue Emerging Topics in Hardware Security)
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Leveraging Neural Trojan Side-Channels for Output Exfiltration
by
Vincent Meyers, Michael Hefenbrock, Dennis Gnad and Mehdi Tahoori
Cryptography 2025, 9(1), 5; https://doi.org/10.3390/cryptography9010005 - 7 Jan 2025
Abstract
Neural networks have become pivotal in advancing applications across various domains, including healthcare, finance, surveillance, and autonomous systems. To achieve low latency and high efficiency, field-programmable gate arrays (FPGAs) are increasingly being employed as accelerators for neural network inference in cloud and edge
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Neural networks have become pivotal in advancing applications across various domains, including healthcare, finance, surveillance, and autonomous systems. To achieve low latency and high efficiency, field-programmable gate arrays (FPGAs) are increasingly being employed as accelerators for neural network inference in cloud and edge devices. However, the rising costs and complexity of neural network training have led to the widespread use of outsourcing of training, pre-trained models, and machine learning services, raising significant concerns about security and trust. Specifically, malicious actors may embed neural Trojans within NNs, exploiting them to leak sensitive data through side-channel analysis. This paper builds upon our prior work, where we demonstrated the feasibility of embedding Trojan side-channels in neural network weights, enabling the extraction of classification results via remote power side-channel attacks. In this expanded study, we introduced a broader range of experiments to evaluate the robustness and effectiveness of this attack vector. We detail a novel training methodology that enhanced the correlation between power consumption and network output, achieving up to a 33% improvement in reconstruction accuracy over benign models. Our approach eliminates the need for additional hardware, making it stealthier and more resistant to conventional hardware Trojan detection methods. We provide comprehensive analyses of attack scenarios in both controlled and variable environmental conditions, demonstrating the scalability and adaptability of our technique across diverse neural network architectures, such as MLPs and CNNs. Additionally, we explore countermeasures and discuss their implications for the design of secure neural network accelerators. To the best of our knowledge, this work is the first to present a passive output recovery attack on neural network accelerators, without explicit trigger mechanisms. The findings emphasize the urgent need to integrate hardware-aware security protocols in the development and deployment of neural network accelerators.
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(This article belongs to the Special Issue Emerging Topics in Hardware Security)
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Reversible Data Hiding in Absolute Moment Block Truncation Codes via Arithmetical and Logical Differential Coding
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Ching-Chun Chang, Yijie Lin, Jui-Chuan Liu and Chin-Chen Chang
Cryptography 2025, 9(1), 4; https://doi.org/10.3390/cryptography9010004 - 30 Dec 2024
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To reduce bandwidth usage in communications, absolute moment block truncation coding is employed to compress cover images. Confidential data are embedded into compressed images using reversible data-hiding technology for purposes such as image management, annotation, or authentication. As data size increases, enhancing embedding
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To reduce bandwidth usage in communications, absolute moment block truncation coding is employed to compress cover images. Confidential data are embedded into compressed images using reversible data-hiding technology for purposes such as image management, annotation, or authentication. As data size increases, enhancing embedding capacity becomes essential to accommodate larger volumes of secret data without compromising image quality or reversibility. Instead of using conventional absolute moment block truncation coding to encode each image block, this work proposes an effective reversible data-hiding scheme that enhances the embedding results by utilizing the traditional set of values: a bitmap, a high value, and a low value. In addition to the traditional set of values, a value is calculated using arithmetical differential coding and may be used for embedding. A process involving joint neighborhood coding and logical differential coding is applied to conceal the secret data in two of the three value tables, depending on the embedding capacity evaluation. An indicator is recorded to specify which two values are involved in the embedding process. The embedded secret data can be correctly extracted using a corresponding two-stage extraction process based on the indicator. To defeat the state-of-the-art scheme, bitmaps are also used as carriers in our scheme yet are compacted even more with Huffman coding. To reconstruct the original image, the low and high values of each block are reconstructed after data extraction. Experimental results show that our proposed scheme typically achieves an embedding rate exceeding 30%, surpassing the latest research by more than 2%. Our scheme reaches outstanding embedding rates while allowing the image to be perfectly restored to its original absolute moment block truncation coding form.
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Open AccessReview
Elliptic Curve Cryptography with Machine Learning
by
Jihane Jebrane, Akram Chhaybi, Saiida Lazaar and Abderrahmane Nitaj
Cryptography 2025, 9(1), 3; https://doi.org/10.3390/cryptography9010003 - 30 Dec 2024
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Elliptic Curve Cryptography (ECC) is a technology based on the arithmetic of elliptic curves used to build strong and efficient cryptosystems and infrastructures. Several ECC systems, such as the Diffie–Hellman key exchange and the Elliptic Curve Digital Signature Algorithm, are deployed in real-life
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Elliptic Curve Cryptography (ECC) is a technology based on the arithmetic of elliptic curves used to build strong and efficient cryptosystems and infrastructures. Several ECC systems, such as the Diffie–Hellman key exchange and the Elliptic Curve Digital Signature Algorithm, are deployed in real-life applications to enhance the security and efficiency of digital transactions. ECC has gained even more importance since the introduction of Bitcoin, the peer-to-peer electronic cash system, by Satoshi Nakamoto in 2008. In parallel, the integration of artificial intelligence, particularly machine learning, in various applications has increased the demand for robust cryptographic systems to ensure safety and security. In this paper, we present an overview of machine learning and Elliptic Curve Cryptography algorithms. We begin with a detailed review of the main ECC systems and evaluate their efficiency and security. Subsequently, we investigate potential applications of machine learning-based techniques to enhance the security and performance of ECC. This study includes the generation of optimal parameters for ECC systems using machine learning algorithms.
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Open AccessArticle
Partial Exposure Attacks Against a Family of RSA-like Cryptosystems
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George Teşeleanu
Cryptography 2025, 9(1), 2; https://doi.org/10.3390/cryptography9010002 - 28 Dec 2024
Abstract
An RSA generalization using complex integers was introduced by Elkamchouchi, Elshenawy and Shaban in 2002. This scheme was further extended by Cotan and Teșeleanu to Galois fields of order . In this generalized framework, the key equation is
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An RSA generalization using complex integers was introduced by Elkamchouchi, Elshenawy and Shaban in 2002. This scheme was further extended by Cotan and Teșeleanu to Galois fields of order . In this generalized framework, the key equation is , where p and q are prime numbers. Note that the classical RSA and Elkamchouchi et al.’s key equations are special cases, namely, when and . In addition to introducing this generic family, Cotan and Teșeleanu described a continued fractions attack capable of recovering the secret key d if . This bound was later improved by Teșeleanu using a lattice-based method. In this paper, we explore other lattice attacks that could lead to factoring the modulus , namely, we propose a series of partial exposure attacks that can aid an adversary in breaking this family of cryptosystems if certain conditions hold.
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Open AccessArticle
Security Proof of Single-Source Shortest Distance Protocols Built on Secure Multiparty Computation Protocols
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Mohammad Anagreh and Peeter Laud
Cryptography 2025, 9(1), 1; https://doi.org/10.3390/cryptography9010001 - 26 Dec 2024
Abstract
Secure secret-sharing Single-Source Shortest Distance (SSSD) protocols, based on secure multiparty computation (SMC), offer a promising solution for securely distributing and managing sensitive information among multiple parties. However, formal security proofs for these protocols have largely been unexplored. This paper addresses this gap
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Secure secret-sharing Single-Source Shortest Distance (SSSD) protocols, based on secure multiparty computation (SMC), offer a promising solution for securely distributing and managing sensitive information among multiple parties. However, formal security proofs for these protocols have largely been unexplored. This paper addresses this gap by providing the first security proof for the SSSD protocols using the privacy-preserving Bellman–Ford protocols. These new protocols offer significant enhancements in efficiency, particularly in handling large-scale graphs due to parallel computation. In our previous work, published in MDPI Cryptography, we introduced these protocols and presented extensive experiments on the Sharemind system that demonstrated their efficiency. However, that work did not include security proofs. Building on this foundation, the current paper rigorously proves the security of these protocols, offering valuable insights into their robustness and reliability. Furthermore, we discuss the adversarial model, security definitions, cryptographic assumptions, and sophisticated reduction techniques employed in the proof. This paper not only validates the security of the proposed protocols but also provides a detailed comparison of their performance with existing methods, highlighting their strengths and potential for future research in the field.
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(This article belongs to the Topic Recent Advances in Security, Privacy, and Trust)
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Two-Party Threshold Private Set Intersection Protocols from Lightweight Cryptographic Primitives
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Shengnan Zhao, Chuan Zhao, Yuchen Huang, Xiangfu Song and Qiuliang Xu
Cryptography 2024, 8(4), 58; https://doi.org/10.3390/cryptography8040058 - 22 Dec 2024
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Private Set Intersection (PSI) is a significant application of interest within Secure Multi-party Computation (MPC), even though we are still in the early stages of deploying MPC solutions to real-world problems. Threshold PSI (tPSI), a variant of PSI, allows two parties to determine
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Private Set Intersection (PSI) is a significant application of interest within Secure Multi-party Computation (MPC), even though we are still in the early stages of deploying MPC solutions to real-world problems. Threshold PSI (tPSI), a variant of PSI, allows two parties to determine the intersection of their respective sets only if the cardinality of the intersection is at least (or less than) a specified threshold t. In this paper, we propose a generic construction for two-party tPSI that extensively utilizes Oblivious Transfer (OT). Our approach is based on lightweight primitives and avoids costly public-key systems such as homomorphic encryption. We start by introducing the secret-sharing private membership test that is based on the secret-sharing private equality test . The enables tPSI to be scaled for a wide range of practical applications, particularly benefiting parties with limited computational resources. Consequently, two distinct two-party tPSI protocols can be efficiently implemented: over-threshold PSI ( ) and under-threshold PSI . In addition, we propose a lightweight two-party tPSI with limited leakage and a generic precomputing OT suitable for phased implementation. Experimental performance demonstrates that our protocols are highly efficient and computationally friendly, thus paving the way for broader deployment of tPSI solutions.
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Open AccessFeature PaperArticle
On the Proof of Ownership of Digital Wallets
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Chen Wang, Zi-Yuan Liu and Masahiro Mambo
Cryptography 2024, 8(4), 57; https://doi.org/10.3390/cryptography8040057 - 18 Dec 2024
Abstract
With the widespread adoption and increasing application of blockchain technology, cryptocurrency wallets used in Bitcoin and Ethereum play a crucial role in facilitating decentralized asset management and secure transactions. However, wallet security relies heavily on private keys, with insufficient attention to the risks
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With the widespread adoption and increasing application of blockchain technology, cryptocurrency wallets used in Bitcoin and Ethereum play a crucial role in facilitating decentralized asset management and secure transactions. However, wallet security relies heavily on private keys, with insufficient attention to the risks of theft and exposure. To address this issue, Chaum et al. (ACNS’21) proposed a “proof of ownership” method using a “backup key” to prove ownership of private keys even when exposed. However, their interactive proof approach is inefficient in large-scale systems and vulnerable to side-channel attacks due to the long key generation time. Other related schemes also suffer from low efficiency and complex key management, increasing the difficulty of securely storing backup keys. In this paper, we present an efficient, non-interactive proof generation approach for ownership of secret keys using a single backup key. Our approach leverages non-interactive zero-knowledge proofs and symmetric encryption, allowing users to generate multiple proofs with one fixed backup key, simplifying key management. Additionally, our scheme resists quantum attacks and provides a fallback signature. Our new scheme can be proved to capture unforgeability under the computational indistinguishability from the Uniformly Random Distribution property of a proper hash function and soundness in the quantum random oracle model. Experimental results indicate that our approach achieves a short key generation time and enables an efficient proof generation scheme in large-scale decentralized systems. Compared with state-of-the-art schemes, our approach is applicable to a broader range of scenarios due to its non-interactive nature, short key generation time, high efficiency, and simplified key management system.
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Open AccessArticle
A Matrix Multiplication Approach to Quantum-Safe Cryptographic Systems
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Luis Adrián Lizama-Pérez
Cryptography 2024, 8(4), 56; https://doi.org/10.3390/cryptography8040056 - 15 Dec 2024
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This paper introduces a novel approach based on matrix multiplication in , which enables methods for public key exchange, user authentication, digital signatures, blockchain integration, and homomorphic encryption. Unlike traditional algorithms that rely on integer factorization or discrete
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This paper introduces a novel approach based on matrix multiplication in , which enables methods for public key exchange, user authentication, digital signatures, blockchain integration, and homomorphic encryption. Unlike traditional algorithms that rely on integer factorization or discrete logarithms, our approach utilizes matrix factorization, rendering it resistant to current quantum cryptanalysis techniques. This method enhances confidentiality by ensuring secure communication and facilitating user authentication through public key validation. We have incorporated a method that allows a Certification Authority to certify the public keys. Furthermore, the incorporation of digital signatures ensures nonrepudiation, while the system functions as a blockchain technology to enhance transaction security. A key innovation of this approach is its capability to perform homomorphic encryption. Our approach has practical applications in artificial intelligence, robotics, and image processing.
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(This article belongs to the Special Issue Advances in Authentication, Authorization and Privacy for Securing Smart Communications)
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Improving the Security of the LCB Block Cipher Against Deep Learning-Based Attacks
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Indrakanti Aishwarya, Lakshmy Koduvayur Viswanathan, Chungath Srinivasan, Girish Mishra, Saibal K. Pal and M. Sethumadhavan
Cryptography 2024, 8(4), 55; https://doi.org/10.3390/cryptography8040055 - 2 Dec 2024
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This study presents a robust version of Light Cipher Block (LCB) by addressing the vulnerabilities identified in previous versions. The vulnerabilities in LCB, including a linear S-Box, improper bit shuffling, and subkey reusability, were thoroughly examined. To overcome these weaknesses, a modified version
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This study presents a robust version of Light Cipher Block (LCB) by addressing the vulnerabilities identified in previous versions. The vulnerabilities in LCB, including a linear S-Box, improper bit shuffling, and subkey reusability, were thoroughly examined. To overcome these weaknesses, a modified version called Secure LCB is introduced, incorporating changes to the P-Box and key generation algorithm. Motivated by Gohr’s work at CRYPTO’19, this paper investigates the use of a neural distinguisher built upon a 1-dimensional convolutional neural network (1-d CNN). The deep learning model is tasked with identifying ciphertexts that have a specific, controlled difference in their inputs, as opposed to those with random input differences. The evaluation of the proposed Secure LCB using the neural distinguisher suggests that the modifications made to LCB have effectively enhanced its resistance against the neural distinguisher’s classification. This highlights the importance of addressing vulnerabilities in cryptographic systems and showcases the potential of machine learning techniques in cryptanalysis.
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Open AccessArticle
New Weak Keys with Parity Patterns in the RC4 Stream Cipher
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Evaristo José Madarro-Capó, Carlos Miguel Legón-Pérez , Guillermo Sosa-Gómez and Omar Rojas
Cryptography 2024, 8(4), 54; https://doi.org/10.3390/cryptography8040054 - 27 Nov 2024
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The RC4 cryptographic algorithm is the most extensively studied stream cipher of the past two decades. This extensive research has resulted in numerous publications, many of which identify various vulnerabilities. Although these vulnerabilities do not preclude the correct use of the algorithm, they
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The RC4 cryptographic algorithm is the most extensively studied stream cipher of the past two decades. This extensive research has resulted in numerous publications, many of which identify various vulnerabilities. Although these vulnerabilities do not preclude the correct use of the algorithm, they complicate its practical implementation. In this paper, we present a novel weakness in the RC4 cipher. Our findings indicate that, for input keys exhibiting certain patterns, the parity of the values in the output permutation of the KSA can be determined with high probability from the parity of its position in the output permutation. Furthermore, the use of keys with these specific patterns leads to noticeable distortions in several bytes of the RC4 output.
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(This article belongs to the Special Issue Advances in Symmetric Cryptography and Data Integrity)
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Implantable Medical Device Security
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Luigi Catuogno and Clemente Galdi
Cryptography 2024, 8(4), 53; https://doi.org/10.3390/cryptography8040053 - 15 Nov 2024
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Implantable medical devices, or IMDs for short, are medical instruments that are placed into the human body through surgery. IMDs are typically used for treating chronic diseases. Currently available IMDs are capable of communicating using wireless channels with other devices, either in close
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Implantable medical devices, or IMDs for short, are medical instruments that are placed into the human body through surgery. IMDs are typically used for treating chronic diseases. Currently available IMDs are capable of communicating using wireless channels with other devices, either in close proximity or even connected to the Internet, making IMDs part of the Internet of Medical Things. This capability opens the possibility of developing a wide range of services, like remote patient data control, localization in case of emergency, or telemedicine, which can improve patients’ lifestyle. On the other hand, given the limited resources of such tiny devices, and the access to the Internet, there are numerous security issues to be considered when designing and deploying IMDs and their support infrastructures. In this paper, we highlight security problems related to Internet-connected IMDs, and survey some solutions that have been presented in the literature.
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(This article belongs to the Special Issue Emerging Topics in Hardware Security)
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An Anonymous Authenticated Key Agreement Scheme for Telecare Medical Information Systems
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Ghassan Hameed Faraj, Kamal Shahtalebi and Hamid Mala
Cryptography 2024, 8(4), 52; https://doi.org/10.3390/cryptography8040052 - 13 Nov 2024
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With the rapid development of information technology from one side and the experience of the COVID-19 pandemic from the other side, people presently prefer to access healthcare services remotely. Telecare Medical Information System (TMIS) provides more flexible, faster, and more convenient e-healthcare services
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With the rapid development of information technology from one side and the experience of the COVID-19 pandemic from the other side, people presently prefer to access healthcare services remotely. Telecare Medical Information System (TMIS) provides more flexible, faster, and more convenient e-healthcare services available to all people, particularly those who lack access to physicians due to their geographical restrictions. However, due to the sensitivity of medical information, preventing unauthorized access to patient data and preserving patient privacy is crucial. In this paper, we propose an authenticated key agreement scheme for TMIS to preserve the privacy of the patient’s identity from all internal (even the health server and the physician) and external entities. Moreover, the physician’s identity is kept secret from all external entities. Formal and informal security analysis of the proposed scheme indicates that it is secure against all attacks in the context.
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Open AccessFeature PaperArticle
A Secure Approach Out-of-Band for e-Bank with Visual Two-Factor Authorization Protocol
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Laerte Peotta de Melo, Dino Macedo Amaral, Robson de Oliveira Albuquerque, Rafael Timóteo de Sousa Júnior, Ana Lucila Sandoval Orozco and Luis Javier García Villalba
Cryptography 2024, 8(4), 51; https://doi.org/10.3390/cryptography8040051 - 11 Nov 2024
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The article presents an innovative approach for secure authentication in internet banking transactions, utilizing an Out-of-Band visual two-factor authorization protocol. With the increasing rise of cyber attacks and fraud, new security models are needed that ensure the integrity, authenticity, and confidentiality of financial
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The article presents an innovative approach for secure authentication in internet banking transactions, utilizing an Out-of-Band visual two-factor authorization protocol. With the increasing rise of cyber attacks and fraud, new security models are needed that ensure the integrity, authenticity, and confidentiality of financial transactions. The identified gap lies in the inability of traditional authentication methods, such as TANs and tokens, to provide security in untrusted terminals. The proposed solution is the Dynamic Authorization Protocol (DAP), which uses mobile devices to validate transactions through visual codes, such as QR codes. Each transaction is assigned a unique associated code, and the challenge must be responded to within 120 s. The customer initiates the transaction on a computer and independently validates it on their mobile device using an out-of-band channel to prevent attacks such as phishing and man-in-the-middle. The methodology involves implementing a prototype in Java ME for Android devices and a Java application server, creating a practical, low-computational-cost system, accessible for use across different operating systems and devices. The protocol was tested in real-world scenarios, focusing on ensuring transaction integrity and authenticity. The results show a successful implementation at Banco do Brasil, with 3.6 million active users, demonstrating the efficiency of the model over 12 years of use without significant vulnerabilities. The DAP protocol provides a robust and effective solution for securing banking transactions and can be extended to other authentication environments, such as payment terminals and point of sale devices.
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Open AccessFeature PaperArticle
Quantum Security of a Compact Multi-Signature
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Shaoquan Jiang
Cryptography 2024, 8(4), 50; https://doi.org/10.3390/cryptography8040050 - 28 Oct 2024
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With the rapid advances in quantum computing, quantum security is now an indispensable property for any cryptographic system. In this paper, we study how to prove the security of a complex cryptographic system in the quantum random oracle model. We first give a
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With the rapid advances in quantum computing, quantum security is now an indispensable property for any cryptographic system. In this paper, we study how to prove the security of a complex cryptographic system in the quantum random oracle model. We first give a variant of Zhandry’s compressed random oracle (CStO), called a compressed quantum random oracle with adaptive special points (CStOs). Then, we extend the on-line extraction technique of Don et al. (EUROCRYPT’22) from CStO to . We also extend the random experiment technique of Liu and Zhandry (CRYPTO’19) for extracting the query that witnesses the future adversarial output. With these preparations, a systematic security proof in the quantum random oracle model can start with a random CStO experiment (that extracts the witness for the future adversarial output) and then converts this game to one involving . Next, the online extraction technique for can be applied to extract the witness for any online commitment. With this strategy, we give a security proof of our recent compact multi-signature framework that is converted from any weakly secure linear ID scheme. We also prove the quantum security of our recent lattice realization of this linear ID scheme by iteratively applying the weakly collapsing protocol technique of Liu and Zhandry (CRYPTO 2019). Combining these two results, we obtain the first quantum security proof for a compact multi-signature.
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Open AccessArticle
Design and Performance Evaluation of an Authentic End-to-End Communication Model on Large-Scale Hybrid IPv4-IPv6 Virtual Networks to Detect MITM Attacks
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Zeeshan Ashraf, Adnan Sohail and Muddesar Iqbal
Cryptography 2024, 8(4), 49; https://doi.org/10.3390/cryptography8040049 - 28 Oct 2024
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After the end of IPv4 addresses, the Internet is moving towards IPv6 address architecture quickly with the support of virtualization techniques worldwide. IPv4 and IPv6 protocols will co-exist long during the changeover process. Some attacks, such as MITM attacks, do not discriminate by
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After the end of IPv4 addresses, the Internet is moving towards IPv6 address architecture quickly with the support of virtualization techniques worldwide. IPv4 and IPv6 protocols will co-exist long during the changeover process. Some attacks, such as MITM attacks, do not discriminate by appearance and affect IPv4 and IPv6 address architectures. In an MITM attack, the attacker secretly captures the data, masquerades as the original sender, and sends it toward the receiver. The receiver replies to the attacker because the receiver does not authenticate the source. Therefore, the authentication between two parties is compromised due to an MITM attack. The existing authentication schemes adopt complicated mathematical procedures. Therefore, the existing schemes increase computation and communication costs. This paper proposes a lightweight and authentic end-to-end communication model to detect MITM attacks using a pre-shared symmetric key. In addition, we implement and analyze the performance of our proposed security model on Linux-based virtual machines connected to large-scale hybrid IPv4-IPv6 virtual networks. Moreover, security analyses prove the effectiveness of our proposed model. Finally, we compare the performance of our proposed security model with existing models in terms of computation cost and communication overhead.
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Open AccessArticle
Post-Quantum Secure ID-Based (Threshold) Linkable Dual-Ring Signature and Its Application in Blockchain Transactions
by
Wen Gao, Haoyuan Yao, Baodong Qin, Xiaoli Dong, Zhen Zhao and Jiayu Zeng
Cryptography 2024, 8(4), 48; https://doi.org/10.3390/cryptography8040048 - 28 Oct 2024
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Ring signatures are widely used in e-voting, anonymous whistle-blowing systems, and blockchain transactions. However, due to the anonymity of ring signatures, a signer can sign the same message multiple times, potentially leading to repeated voting or double spending in blockchain transactions. To address
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Ring signatures are widely used in e-voting, anonymous whistle-blowing systems, and blockchain transactions. However, due to the anonymity of ring signatures, a signer can sign the same message multiple times, potentially leading to repeated voting or double spending in blockchain transactions. To address these issues in blockchain transactions, this work constructs an identity-based linkable ring signature scheme based on the hardness of the lattice-based Module Small Integer Solution (M-SIS) assumption, which is hard even for quantum attackers. The proposed scheme is proven to be anonymous, unforgeable, linkable, and nonslanderable in the random oracle model. Compared to existing identity-based linkable ring signature (IBLRS) schemes of linear size, our signature size is relatively smaller, and this advantage is more pronounced when the number of ring members is small. We provide approximate signature size data for ring members ranging from 2 to 2048. When the number of ring members is 16 (or 512. resp.), the signature size of our scheme is 11.40 KB (or 24.68 KB, respectively). Finally, a threshold extension is given as an additional scheme with specifications and security analysis.
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Open AccessArticle
Next-Generation Block Ciphers: Achieving Superior Memory Efficiency and Cryptographic Robustness for IoT Devices
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Saadia Aziz, Ijaz Ali Shoukat, Mohsin Iftikhar, Mohsin Murtaza, Abdulmajeed M. Alenezi, Cheng-Chi Lee and Imran Taj
Cryptography 2024, 8(4), 47; https://doi.org/10.3390/cryptography8040047 - 23 Oct 2024
Abstract
Traditional cryptographic methods often need complex designs that require substantial memory and battery power, rendering them unsuitable for small handheld devices. As the prevalence of these devices continues to rise, there is a pressing need to develop smart, memory-efficient cryptographic protocols that provide
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Traditional cryptographic methods often need complex designs that require substantial memory and battery power, rendering them unsuitable for small handheld devices. As the prevalence of these devices continues to rise, there is a pressing need to develop smart, memory-efficient cryptographic protocols that provide both high speed and robust security. Current solutions, primarily dependent on dynamic permutations, fall short in terms of encryption and decryption speeds, the cryptographic strength, and the memory efficiency. Consequently, the evolution of lightweight cryptographic algorithms incorporating randomised substitution properties is imperative to meet the stringent security demands of handheld devices effectively. In this paper, we present an advanced design of lightweight block ciphers that enhances traditional dynamic permutations with innovative randomised substitutions. This design utilises straightforward randomized encryption methods such as XOR, nibble swap, count ones, and left shift. The cryptographic robustness of our proposed block cipher has been rigorously tested through several standardised statistical tests, as recommended by the National Institute of Standards and Technology (NIST). These evaluations confirm that our algorithm maintains strong cryptographic properties with randomised substitutions and outperforms existing models in several key aspects. Moreover, comparative assessments reveal that our algorithm achieves a throughput of 853.31 Kbps while consuming only 1510 bytes of memory and demonstrating over 60% avalanche properties, significantly outperforming other solutions in terms of CPU utilisation and memory consumption. These results underscore the efficacy of our approach in fulfilling the advanced security requirements of modern handheld devices.
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(This article belongs to the Special Issue Advances in Authentication, Authorization and Privacy for Securing Smart Communications)
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Open AccessArticle
Lightweight Mutually Authenticated Key Exchange with Physical Unclonable Functions
by
Cyrus Minwalla, Jim Plusquellic and Eirini Eleni Tsiropoulou
Cryptography 2024, 8(4), 46; https://doi.org/10.3390/cryptography8040046 - 19 Oct 2024
Abstract
Authenticated key exchange is desired in scenarios where two participants must exchange sensitive information over an untrusted channel but do not trust each other at the outset of the exchange. As a unique hardware-based random oracle, physical unclonable functions (PUFs) can embed cryptographic
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Authenticated key exchange is desired in scenarios where two participants must exchange sensitive information over an untrusted channel but do not trust each other at the outset of the exchange. As a unique hardware-based random oracle, physical unclonable functions (PUFs) can embed cryptographic hardness and binding properties needed for a secure, interactive authentication system. In this paper, we propose a lightweight protocol, termed PUF-MAKE, to achieve bilateral mutual authentication between two untrusted parties with the help of a trusted server and secure physical devices. At the end of the protocol, both parties are authenticated and possess a shared session key that they can use to encrypt sensitive information over an untrusted channel. The PUF’s underlying entropy hardness characteristics and the key-encryption-key (KEK) primitive act as the root of trust in the protocol’s construction. Other salient properties include a lightweight construction with minimal information stored on each device, a key refresh mechanism to ensure a fresh key is used for every authentication, and robustness against a wide range of attacks. We evaluate the protocol on a set of three FPGAs and a desktop server, with the computational complexity calculated as a function of primitive operations. A composable security model is proposed and analyzed considering a powerful adversary in control of all communications channels. In particular, session key confidentiality is proven through formal verification of the protocol under strong attacker (Dolev-Yao) assumptions, rendering it viable for high-security applications such as digital currency.
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(This article belongs to the Section Hardware Security)
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