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Advancements in computing and communication technology have increased the number of devices connected to the Internet, leading to the emergence of the Internet of Things (IoT) technology. However, currently available network security measures are mainly designed for devices with higher computing power and cannot be directly applied to IoT devices. Client authentication is a fundamental aspect of security in IoT systems and is often achieved using digital signatures. Current IoT client authentication methods, such as RSA and ECDSA, are resource-intensive and vulnerable to attacks. Non-interactive zero-knowledge proof approaches are more suitable for IoT networks. MQTT is a widely used communication protocol in the IoT environment, but the client authentication feature of the standard MQTT protocol is poor. This paper proposes improving the elliptic curve cryptography-based non-interactive zero-knowledge proof authentication algorithm ECDSA. The proposed algorithm, T-ECDSA, uses a timestamp-based key to encrypt/decrypt the signature, valid only for a short period, making signature reuse invalid. The T-ECDSA is incorporated into the MQTT broker to avoid the requirement of a different dedicated server for authentication purpose. The experimental results demonstrate better security and improved time and execution complexity for the T-ECDSA compared to the standard ECDSA. [ABSTRACT FROM AUTHOR]

In Eurocrypt'96, the concept of Designated Verifier Signature was proposed. Such signatures can only be verified by a single designated verifier specified during signature creation. However, there exist situations in which the signer, as well as the designated verifier, should be equipped with the ability to check the validity of the signature. At the same time, either of them should be able to help third parties to verify the signature. This is achieved by Directed Signature Schemes. In this paper, we consider directed signatures in the certificateless cryptography setting and propose an efficient pairing-free certificateless directed signature (CLDS) scheme. Then, we prove that the proposed CLDS scheme meets the needed security requirements in the random oracle model and under the assumption of the hardness of discrete logarithm and Gap Diffie-Hellman problems. We also compare the proposed scheme with the related ones to indicate the overall superiority of the proposed CLDS scheme. [ABSTRACT FROM AUTHOR]

In vehicular energy networks (VENs) operating in smart health care systems (SHaCarS), reputation of vehicles, i.e., ambulances, plays an important role as all functions depend upon it including message sharing, energy trading, etc. Keeping this in view, this paper presents a reputation management scheme. To ensure that the proposed scheme is secure and transparent, Blockchain (BC) technology is used. In the proposed model, the registration of ambulances is performed through a certificate authority (CA). Later, a pseudo mechanism is designed using Elliptic Curve Digital Signature Algorithm, which ensures conditional anonymity and traceability. The ambulances are provided with the pseudo identities, which are mapped with the real identities to prevent disputes. Besides, the proposed scheme uses a Shamir secret sharing (SSS) algorithm to enable distributed revocation in BC based VENs operating in SHaCarS. In addition, the ambulances' reputation information is stored in interplanetary file system (IPFS) in an efficient manner. The hashes are generated by IPFS upon data storage, which are then stored in BC. The performance evaluation of the proposed system is done via extensive simulations. The results show 18–20% reduction in computational overhead and 35–40% reduction in storage overhead. The proposed system's robustness is tested by inducing the 51% attack and the replay attack. In addition, the security analysis of the smart contract is performed using Oyente. The results show that the system proposed for reputation management in the underlying work is robust and computationally efficient. [ABSTRACT FROM AUTHOR]

The development of information and communication technology (ICT) has driven the rapid growth of electronic transactions. The use of electronic signatures (TTE) is also a practical solution in electronic transactions. This research aims to determine the validity of TTE in electronic transactions based on PP No. 71 of 2019. This research uses normative legal research methods with a juridical-normative approach. Research data was obtained from literature studies of statutory regulations, books, scientific journals and other secondary legal sources. Data were analyzed qualitatively using interpretation and description methods. The research results show that based on Government Regulation (PP) no. 71 of 2019 concerning Implementation of Electronic Systems and Transactions, electronic signatures are recognized as a valid form of signature in electronic transactions. Electronic Signatures used in Electronic Transactions can be generated through various signing procedures. Electronic Signatures have legal force and legal consequences as long as they meet the requirements. So it can be concluded that electronic signatures have validity and legal force that is recognized in electronic transactions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Domain reconstruction imposes honeycomb and kagome superstructures in twisted MoS 2 bilayer with small twist angles. • Superstructures introduce valence bands resembling band structures of graphene (θ → 0 °) and hexagonal boron nitride (θ → 60 °). • Flat bands emerge for small twist angles. For twists close to 60°, super-heavy fermions govern the valence band. Angeli and MacDonald reported a superlattice-imposed Dirac band in twisted bilayer molybdenum disulphide (tBL MoS 2) for small twist angles towards the R h M (parallel) stacking. Using a hierarchical set of theoretical methods, we show that the superlattices differ for twist angles with respect to metastable R h M (0°) and lowest-energy H h h (60°) configurations. When approaching R h M stacking, identical domains with opposite spatial orientation emerge. They form a honeycomb superlattice, yielding Dirac bands and a lateral spin texture distribution with opposite-spin-occupied K and K' valleys. Small twist angles towards the H h h configuration (60°) generate H h h and H h X stacking domains of different relative energies and, hence, different spatial extensions. This imposes a symmetry break in the moiré cell, which opens a gap between the two top-valence bands, which become flat already for relatively small moiré cells. The superlattices impose electronic superstructures resembling graphene and hexagonal boron nitride into trivial semiconductor MoS 2. [ABSTRACT FROM AUTHOR]

Cross-chain transaction technologies have greatly promoted the scalability of cryptocurrencies, which then facilitates the development of Metaverse applications. However, existing solutions rely heavily on centralized middleware (notary) or smart contracts. These schemes lack privacy considerations, and users' cross-chain transactions are easy to master by other parties. Some signature-based payment schemes have good privacy but do not support multi-party cross-chain protocols or rely heavily on some time assumptions. The uncertainty of user behavior makes it difficult to design a secure multi-party cross-chain protocol. To solve these problems, we investigate how to design a secure multi-party cross-chain transaction protocol with offline tolerance. We propose a new signature algorithm called the pre-adaptor signature scheme, an extension of the adaptor signature scheme. The pre-adaptor signature scheme combines the multi-signature and adaptor signature schemes, which can realize the secret transmission channel between multiple parties. To provide offline tolerance, we encode our protocol into the P2SH script. Our protocol provides better privacy due to no dependence on smart contracts. The performance evaluation was conducted with ten participants. For each participant of our cross-chain protocol, the initialization and execution process can be performed in 3 milliseconds and with 6 k bytes of communication overhead at most. The cost increases linearly with the increase in the number of participants. [ABSTRACT FROM AUTHOR]

Popularity of cryptocurrencies like bitcoin and Ethereum is exponentially increasing in global financial market whose market capitalization is $400 and $250 billions, respectively (Patel and Doshi, 2021). Due to its huge growing popularity and being decentralized unsupervised protocol, potential attackers steal the cryptocurrency by changing the ownership of it without the consent of cryptocurrency owners. Bitcoin uses elliptic curve digital signature algorithm (ECDSA) for signing its transactions. The underlying concept of ECDSA is elliptic curve discrete logarithm problem (ECDLP) with assumption that solving ECDLP is infeasible and is a computationally hard problem. Some attacks on ECDSA involve complicated Fourier analysis and lattice mathematics. Leaking cryptographic keys can be in two forms, namely explicit leak or implicit leak (Brengel and Rossow, 2018). In explicit leak, the cryptographic keys are posted in public knowingly or accidentally, whereas in implicit leak the cryptocurrency or software developers may wrongly apply the cryptographic primitives. Initially we begin with a ECDSA signature to sign a message using private key and validate the generated signature using the shared public key. Then, we use a nonce or a random value to randomize the generated signature. ECDSA nonce bias can be exploited in many ways; for instance, every time we sign, a new verifiable random nonce value is created and way in which the intruder can discover the private key if the signer leaks any one of the nonce value or if same nonce is repeatedly used to sign multiple messages. In contrast to above attack on ECDSA, we use the Lenstra–Lenstra–Lovasz (LLL) method; here, we attack signatures generated from bad nonce or bad random number generator (RAG) on selected NIST and SECP curves. The comparative analysis for each of the curves over leak–weak nonces and with Lenstra–Lenstra–Lovasz method to crack ECDSA is done by considering various parameters such as number of private keys, single nonce, multiple nonces, single signature, multiple signatures of varying bit sizes of length 64 bits, 128 bits, 256 bits, 512 bits, 1024 bits. Also, we clearly show safe and unsafe curves on leak–weak nonces and LLL method with its average computational efficiency across various bit sizes to crack ECDSA. The results demonstrate that leak–weak nonce method performs exponentially better over LLL to crack ECDSA. In addition to finding multiple vulnerabilities on ECDSA and to avoid leak–weak nonces, we use T-of-N threshold signing algorithm using GG20 where nonce k is distributed across N parties unlike having with one single party. We implement our scheme and evaluate it among group of N parties. This paper enables cryptographers to identify efficient ways in which ECDSA can be cracked with leak–weak nonces and LLL algorithm using NIST and SECP curves, kind of attacks that can crack ECDSA and how to safeguard against such attacks. [ABSTRACT FROM AUTHOR]

This paper optimized SeaSign – an isogeny-based digital signature algorithm that combines the class group actions of CSIDH with the notion of Fiat-Shamir with abort. The proposed modification is simple yet powerful, which is the repositioning of the rejection sampling within the algorithm. Additionally, SeaSign is further optimized by using the Huff-Edwards hybrid isogeny. As a result, the signature generation of the proposed SeaSign is approximately 3 times faster than the original version of SeaSign. Additionally, this paper presents the results of performance comparisons with other optimization methods of SeaSign. In conclusion, the proposed algorithm has zero rejection rate so it demonstrates more efficient performance in any scenario.

The article examines the impact of electronic contracts on financial systems, highlighting the changes brought about by financial technologies (FinTech) through electronic contracts as well as digital signatures. The impact of FinTech also extends to markets, transforming the way businesses and institutions interact, including intraorganisational and stakeholder relationships. The article highlights the benefits of e-contracting, such as reduced costs, increased efficiency and process automation. Through FinTech, e-commerce has evolved significantly, facilitating new business models with a digital presence and improving contracting between companies and their customers. Particular attention is paid to electronic signatures, which are considered legal means of signing documents in the digital environment. The article also highlights the evolution of smart contracts, based on blockchain technology, which automate contractual processes and can be concluded without the direct involvement of the parties. Thus, a landscape is emerging in which financial technologies continue to redefine and innovate the global financial system.

A chiral analog of transient absorption spectroscopy, transient circular dichroism (TCD) spectroscopy is an emerging time-resolved method. Both spectroscopic methods can probe the electronic transitions of a sample, and TCD is additionally sensitive to the dynamic aspects of chirality, such as those induced by molecular excitons. Here, we develop a theoretical description of TCD for electronic multi-level models in which the pump pulse is linearly polarized and probe pulse is alternately left- and right-circularly polarized. We derive effective response functions analogous to those often used to describe other four-wave mixing methods and then simulate and analyze TCD spectra for three representative multi-level electronic model systems. We elaborate on the presence and detection of the spectral signatures of electronic coherences. [ABSTRACT FROM AUTHOR]

This work intends to comprehensively analyze the application of blockchain technology in enterprise financial accounting information sharing and address prevalent issues such as information opacity, data tampering, and data security in the current practices. Therefore, it writes smart contracts based on the Ethereum platform to achieve the secure sharing of financial accounting information between enterprises. This work employs a randomized experimental design approach, using a computer-generated random number program to divide 100 enterprises into experimental and control groups, each comprising 50 enterprises. Enterprises in the experimental group share financial accounting information using smart contracts on the Ethereum platform during the experiment. The financial personnel of these enterprises upload reconciled data to the corresponding smart contracts using the enterprise's digital signatures after each month's accounting process. Enterprises in the control group continue to use traditional methods of financial accounting information sharing (such as email and web platforms) to share financial data files directly. Quantitative analysis is performed to compare the data between the experimental and control groups. Empirical results reveal a notable enhancement in information-sharing efficiency by 25.7%, a 19.8% improvement in data accuracy, and a 13.6% reduction in financial information-sharing costs within the experimental group compared to the control group. This work provides compelling evidence that adopting blockchain-based information-sharing methods can effectively elevate data trustworthiness and security. Supported by systematic empirical findings, this work validates the significant potential of blockchain technology in the realm of enterprise financial accounting information sharing. [ABSTRACT FROM AUTHOR]

Quantum secret sharing is widely applied in the fields, such as communications and data transmission. In this paper, we propose an authenticable dynamic quantum multi-secret sharing scheme based on the Chinese remainder theorem. In our scheme, the dynamic update of the participants set is permissible without changing the shared secret. To share multi-secret, the distributor generates corresponding shares based on the Chinese remainder theorem and monotone span program, and the GHZ state acts as the information carrier traveling among the participants in the authorization set; the participants utilize the Hadamard operator and Pauli operators to embed their shares in the traveling particles. In this way, the participants will reconstruct multiple secrets. Furthermore, the proposed quantum digital signature algorithm based on entanglement swapping is utilized to realize the identity authentication between participants. The security analysis shows that the proposed scheme can resist intercept-resend attack, entanglement-measurement attack, internal dishonest participant attack, add or withdraw participant attack, and denial attack. [ABSTRACT FROM AUTHOR]

Background: Advance care planning enables people to record their future health and care wishes and appoint someone as an advocate. An advance directive can be made in the event that a person is incapacitated, so that their wishes are still upheld. The beliefs of the nephrology team might affect patients' choices and willingness to sign an advance directive. To increase the number of dialysis patients who have signed an advance directive, it is necessary to educate the nephrology medical staff. Aim: To explore the intention to sign an advance directive and its related factors among nephrology medical staff. Methods: A cross-sectional and correlational design was used. This study recruited 160 nephrology medical staff. Data were analysed by using the Statistical Package for Social Science 21.0 for Windows. Findings: The results found that the longer someone has worked as part of the nephology medical staff, the more knowledgeable they were about an advance directive. This led to them being more likely to want to sign an advance directive for themselves. Conclusion: In order to improve the knowledge and awareness of advance directives among nephrology medical staff, hospital managers should provide continuing education on this topic. [ABSTRACT FROM AUTHOR]

The risks of misusing new and developing technology are increasing on a daily basis. In these technologies, electronic communication (e-communication) anonymously delivers sensitive information. It is a challenging task in e-communication to conceal the identity of the original users and preserve misuse risk protection (i.e., security and privacy) with low computations. On the other hand, anonymous communication may be detrimental. For security and privacy maintenance, we use the concept of Misuse Risk Protection (MRP) for low computations and High-Performance Computing (HPC). To overcome these challenges, the researchers use the concept of blind signature, blind singcryption and ID-based signcryption for e-communication environments. We analyzed blind and ID-based signcryption schemes and their security hardness, which is based on different Discrete Logarithm Problems (DLP) such as Elliptic Curve DLP (ECDLP), Hyperelliptic Curve DLP (HECDLP), and bilinear pairing etc. In this paper, we also investigated that the proposed schemes attain the desired MRP features, HPC (e.g., low computation and communication overheads) than the existing schemes, which makes the newly proposed scheme more suitable for low-power environments. Finally, all schemes with small key sizes provide low computation and communication overhead. Due to low computation and communication overheads, it is considered efficient. [ABSTRACT FROM AUTHOR]

Internet of Things (IoT) is a rapidly expanding technology composed of devices embedded with sensors, specialized hardware, and software to connect with other devices and servers on the internet. With this rapid expansion, it faces some major hurdles in data secrecy, privacy, and device integrity, and perhaps, in general, digital identity has been a major problem on the internet. The World Wide Web Consortium (W3C) has provided a standardized format through which one can specify his identity called Decentralised Identifiers (DIDs). Blockchain technology, alongside decentralized identifiers and public-key cryptography, offers a peer-to-peer identity and credential management model through self-sovereign identity. Combining the decentralized identity and blockchains provides us with verifiable credentials through which one can verify the identities of transacting peers by decentralized registration and discovery of public keys needed to verify digital signatures. This combined framework is trusted, permissioned, supports device registration and verification along with revocation of device credentials, is secure, respects the privacy of the participating nodes, and maintains the integrity of their data. With several new communication protocols being developed for IoT and leveraging the Blockchain protocols in the domain of IoT, this paper quantitatively compares the performance of the well-known IoT communication protocols such as CoAP, MQTT, and DIDComm in real-time testbed on various parameters, and the results are tabulated. Device data has also been replicated across multiple peers using decentralized storage such as InterPlanetary File System (IPFS). [ABSTRACT FROM AUTHOR]

Elliptic curve cryptography is a widely deployed technology for securing digital communication. It is the basis of many cryptographic primitives such as key agreement protocols, digital signatures, and zero-knowledge proofs. Fast elliptic curve cryptography relies on heavily optimised modular arithmetic operations, which are often tailored to specific micro-architectures. In this article, we study and evaluate optimisations of the popular elliptic curve Curve25519 for ARM processors. We specifically target the ARM NEON single instruction, multiple data (SIMD) architecture, which is a popular architecture for modern smartphones. We introduce a novel representation for 128-bit NEON SIMD vectors, optimised for SIMD parallelisation, to accelerate elliptic curve operations significantly. Leveraging this representation, we implement an extended twisted Edwards curve Curve25519 back-end within the popular Rust library "curve25519-dalek". We extensively evaluate our implementation across multiple ARM devices using both cryptographic benchmarks and the benchmark suite available for the Signal protocol. Our findings demonstrate a substantial back-end speed-up of at least 20% for ARM NEON, along with a noteworthy speed improvement of at least 15% for benchmarked Signal functions. [ABSTRACT FROM AUTHOR]

Wireless sensor networks (WSNs) are a distributed collection of sensor nodes which are distributed geographically in the deployed environment to sense the natural phenomena. The sensed data are transmitted by the nodes using multi-hop communication until it reaches to the base station. Due to its resource-constraint nature of device and its communication in open and unfriendly environment, providing energy optimization along with the secured communication is a major challenge. In this work, a trust-aware neuro-fuzzy-based clustering along with sparrow search optimization algorithm (NF-SSOA) is proposed to provide energy-efficient trust-aware cluster-based secured data transmission in WSNs. The proposed protocol performs effective clustering of the nodes by employing neuro-fuzzy clustering algorithm, and routing is performed by sparrow search optimization algorithm. ECC-based digital signature algorithm is used in the proposed system to provide an efficient lightweight key generation, encryption, decryption, signature generation, and verification and to ensure hop-to-hop authentication of the nodes in WSNs. Moreover, the proposed protocol employs pseudo-random identity generation for performing anonymous authentication during data transmission in the network. The proposed protocol is implemented by using NS3 simulator. The simulation results prove that the proposed protocol improves energy consumption analysis, throughput, network delay, network lifetime, and packet delivery ratio when it is compared with other existing protocols. Moreover, the proposed protocol shows significant potential for resistance to various security and improves the quality of services in the network. [ABSTRACT FROM AUTHOR]

Introduction/purpose: All data exchanged over the Internet as well as other computer networks should be considered exposed to various types of security threats. In light of this, the transmission of voice over applications that do not use any type of crypto-protection allows anyone to discern the content of communication. Since voice transmission requires as little delay as possible, various protocols are used to enable crypto protected real-time communication. This paper presents one solution in a desktop application variant. Methods: The essence in voice exchange systems as well as in other systems where real-time communication is necessary is the establishment of a crypto-protected session which is a virtual secure channel for communication to which only the communicating parties have access. Voice sessions in the application are established with the SIP (Session Initiation Protocol) protocol. The sessions are further protected using the ZRTP (Zimmerman Real-time Transport Protocol) protocol. FusionPBX was used as the SIP server (registrar) for testing purpouses. The application is developed in C++ language using the Qt framework. Results: The final version of the application demostrates that ZRTP and SIP protocols are well suited for establishing crypto protected voice communications with low delay. Conclusion: This solution provides cryptographic functions for data secrecy and the management of cryptographic keys. Improving the solution with digital signatures and certificates will result in additional cryptographic functions: data integrity and personal identification. With this improvement, this solution will be able to withstand modern security threats with low delay [ABSTRACT FROM AUTHOR]

With the rapid development of information technology, electronic signature plays an increasingly important role in people's production practice. However, there are a large number of hackers maliciously stealing information in the network. In order to avoid this phenomenon, we urgently need to strengthen the research on online electronic signature recognition technology. Based on the sparse classification technology of neural model, this paper constructs an online electronic signature recognition model by using convolutional neural network and sparse classification technology. We first extract the local features of online electronic signatures, construct feature vectors and perform sparse representation. Sub-model we construct a scheme for online electronic signature recognition based on neural models and sparse classification techniques using a combination of algorithms. We first extract the local features of online electronic signatures, construct feature vectors and perform sparse representation. At the same time, the features in the training image set are extracted, local feature sets are constructed, feature dictionaries are created, and the vectors in the feature dictionaries are matched with the global sparse vectors constructed by the electronic signatures to be detected, and the matching results are finally obtained. At the same time, the features in the training image set are extracted, the local feature set is constructed, the feature dictionary is created, and the vector in the feature dictionary is matched with the global sparse vector constructed by the electronic signature to be detected, and finally the matching result is obtained. In order to verify the accuracy of the model, we first extracted 1000 respondents for online e-signature recognition experimental results show that the recognition accuracy of online e-signature has been significantly improved. Finally, in order to determine the optimal number of training sets for the model constructed in this experiment, we analyzed the correlation between training and sample size and recognition accuracy. Finally, it was concluded that the recognition accuracy increased with the increase of the number of training samples. Electronic signatures can quickly examine the signature results, and electronic signature recognition can be used to fix and tamper-proof evidence to enhance the security and trustworthiness of signatures, and it is imperative to improve the security of electronic signatures. In this paper, we study online electronic signature recognition technology, using neural model and sparse classification to construct an efficient and accurate recognition model. Experiments show that the model is effective and the number of training samples affects the recognition accuracy. This paper provides a new approach for the development of this technique. When the training samples are greater than 1300, the recognition accuracy is stable at 95%. This research has certain theoretical and practical significance, and promotes the rapid development of online electronic signature recognition. [ABSTRACT FROM AUTHOR]

The aim of this article is to select an applicable framework for modelling the spread of the Hungarian eID card, as an innovation, among the Hungarian population. Using the concepts of the selected theory, a basic model is also outlined, which can serve as a foundation for further research. Keeping the characteristics of the Hungarian eID card in mind, this article compares the various technology acceptance theories. Considering the specialties of the identity document, the Diffusion of Innovations is the most suitable framework for examining the spread of the Hungarian eID card and its electronic functions in Hungary. Through the outlined model, the factors preventing the spread can be identified, and new research directions can also be determined. With the further development of the model, a diffusion plan can be created that would greatly facilitate the spread of the examined electronic identification document. [ABSTRACT FROM AUTHOR]

The article focuses on the expressions of will in electronic contracts, highlighting the unique characteristics of mutual assent in these contracts compared to traditional ones. Topics include the legal provisions governing electronic contracts, the challenges posed by their uniqueness, and the distinction between national and international characteristics of electronic contracts.

Elliptic Curve Cryptography (ECC) is one of the public key cryptosystems that works based on the algebraic models in the form of elliptic curves. Usually, in ECC to implement the encryption, the encoding of data must be carried out on the elliptic curve, which seems to be a preprocessing step. Similarly, after the decryption a post processing step must be conducted for mapping or decoding the corresponding data to the exact point on the elliptic curves. The Memory Mapping (MM) and Koblitz Encoding (KE) are the commonly used encoding models. But both encoding models have drawbacks as the MM needs more memory for processing and the KE needs more computational resources. To overcome these issues the proposed enhanced Koblitz encoding technique is used with the ECC for enhancing the security. The proposed model was compared to the existing model and found to be more efficient in terms of security. The proposed model ensure confidentiality with the encryption technique, Integrity by using the Hashing method, and authenticity and nonrepudiationwith the utilization of digital signature. [ABSTRACT FROM AUTHOR]

The quantum digital signature (QDS) has become a popular research topic in the field of quantum information, due to its information-theoretic security on signing signatures. However, weak coherent sources are often utilized as light sources in most previous QDS protocols, resulting in relative limited secure transmission distance. Here, we propose a four-intensity decoy-state QDS scheme based on heralded single-photon sources (HSPS) and present a concise security analysis in the finite-size scenario. Furthermore, we carry out corresponding experimental demonstrations, and successfully sign messages at 14.4 dB and 24.4 dB, verifying the good performance of implementing QDS with HSPS. [ABSTRACT FROM AUTHOR]

In the field of post-quantum security, isogeny-based cryptography stands out for its ability to fight quantum attacks. One of the key operations in isogeny-based schemes is finite field multiplication, which plays a crucial role in cryptographic protocols such as key exchange and digital signatures. To ensure practical implementations of these schemes, efficient finite field multiplication is essential. In this research, a novel optimization approach, the Crossover-Boosted Water Cycle Algorithm (CB-WCA), to enhance the efficiency of finite field multiplication in isogeny-based cryptography is proposed. By using both the WCA and a crossover method inspired by genetic algorithms, the CB-WCA effectively explores solution areas, aiming for the best solutions. The formulation of the finite field multiplication optimization problem and an objective function that quantifies the efficiency of the multiplication process based on computational cost is presented and defined. The CB-WCA is then applied to find the optimal set of parameters for finite field multiplication algorithms. Extensive experimental evaluations are conducted, comparing the performance of the CB-WCA-optimized algorithms with traditional optimization methods and other metaheuristic algorithms. Through the findings, it is evident that the CB-WCA stands out for its ability to achieve faster execution times and decrease computational costs. Furthermore, the optimized finite field multiplication algorithms are integrated into isogeny-based cryptographic schemes and evaluate their impact on cryptographic protocol efficiency and security. Real-world implementations showcase the practical applicability of the optimized algorithms in hardware and software environments. To ensure the security of the optimized algorithms, rigorous cryptanalysis is performed to verify their resilience against potential attacks, ensuring they meet the highest standards of security. [ABSTRACT FROM AUTHOR]

The current neuropsychiatric nosological categories underlie pragmatic treatment choice, regulation and clinical research but does not encompass biological rationale. However, subgroups of patients suffering from schizophrenia or Alzheimer's disease have more in common than the neuropsychiatric nature of their condition, such as the expression of social dysfunction. The PRISM project presents here initial quantitative biological insights allowing the first steps toward a novel trans-diagnostic classification of psychiatric and neurological symptomatology intended to reinvigorate drug discovery in this area. In this study, we applied spectral clustering on digital behavioural endpoints derived from passive smartphone monitoring data in a subgroup of Schizophrenia and Alzheimer's disease patients, as well as age matched healthy controls, as part of the PRISM clinical study. This analysis provided an objective social functioning characterization with three differential clusters that transcended initial diagnostic classification and was shown to be linked to quantitative neurobiological parameters assessed. This emerging quantitative framework will both offer new ways to classify individuals in biologically homogenous clusters irrespective of their initial diagnosis, and also offer insights into the pathophysiological mechanisms underlying these clusters. [ABSTRACT FROM AUTHOR]

The utilization of handwritten electronic signatures has expanded in various application scenarios, leading to an increased demand for identification. Unlike handwriting signatures, handwritten electronic signatures offer the advantage of extracting dynamic feature data, including writing pressure, velocity, and acceleration. In this study, the Fourier transform was employed to extract 18 characteristics from the time domain and frequency domain of writing pressure, velocity, and acceleration. The experimental findings revealed distinguishable differences between genuine signatures and random forgeries in writing pressure. However, no statistically significant differences were observed in writing velocity and writing acceleration. Moreover, significant differences were detected in most characteristics when comparing genuine signatures with freehand imitation forgeries and tracing imitation forgeries. The canonical discriminant analysis was performed between the genuine and Non‐genuine signatures; the cross‐validation estimated the discriminating power of these characteristics with a satisfactory result. The study proposed a new approach to analyzing handwritten electronic signatures using time‐domain and frequency‐domain characteristics and demonstrated its effectiveness in the examination. [ABSTRACT FROM AUTHOR]

Quantum signature has become a hot topic in the current research of digital signature schemes due to its unconditional security. As a special kind of digital signature, ring signatures are frequently employed in practical situations because of their superior anonymity. In this work, we propose a quantum ring signature scheme based on secret sharing that does not use entanglement states. To guarantee the complete security of the participants' secret keys, the idea of secret sharing is incorporated into the quantum key distribution process during the key distribution stage. Each ring member contributes his private key share to the final verification formula through a recursive relationship throughout the signing and verification phases, and the verifier can utilize his private key share along with the user's public key to confirm the ring members' authenticity; The ε -AS2U hash function is used to encrypt the ring signer's identity during the entire signature process, which assures the signer's identity's complete anonymity, effectively protects the signer's privacy, and is more in line with practical requirements. [ABSTRACT FROM AUTHOR]

Recently, magic-angle twisted bilayer graphene (MATBLG) has emerged with various interaction-driven novel quantum phases at the commensurate fillings of the moiré superlattice, while the charge neutrality point (CNP) remains mostly a trivial insulator. Here, we show an emerging phase of compensated semimetallicity at the CNP of twisted double bilayer graphene (TDBLG), a close cousin of MATBLG, with signatures of electronic correlation. Using electrical and thermal transport, we find two orders of magnitude enhancement of the thermopower at magnetic fields much smaller than the extreme quantum limit, accompanied by large magnetoresistance (~ 2500%) at CNP, providing strong experimental evidence of compensated semimetallicity at CNP of TDBLG. Moreover, at low temperatures, we observe unusual sublinear temperature dependence of resistance. A recent theory1 predicts the formation of an excitonic metal near CNP, where small electron and hole pockets co-exist. We understand this sublinear temperature dependence in terms of critical fluctuations in this theory. Twisted double bilayer graphene has recently become a popular system to investigate strongly correlated phenomenon where the twist angle is a key degree of freedom. Here, the authors investigate thermopower in twisted double bilayer graphene finding a large enhancement of thermopower and magnetoresistance within a small magnetic field near the charge neutrality point, indicating a compensated semimetallic state. [ABSTRACT FROM AUTHOR]

In our research, we discussed the concept of the E-contract in terms of its definition, international and regional guidelines, and national legislation. Since there are conditions for E-signature, we have illustrated them and explained their forms in the first section. In the second section, we discussed the authority of the E-signature in terms of its authority in international and regional guidelines in a first requirement and the protection of the electronic signature technically and criminally in a second requirement. The results and recommendations. Among the most important recommendations, we recommended that the Yemeni legislator quickly amend the texts of the Evidence Law and the Crimes and Penal Code and add texts that accommodate modern electronic means and build authority. The Judiciary has a broad plan to train judges and prosecutors, provide them with modern information knowledge, and raise the level of information efficiency in the professional sector to the judicial authority. [ABSTRACT FROM AUTHOR]

Internet of things (IoT) is a recent developing technology in the field of smart healthcare. But it is difficult to transfer the patient's health record as a centralized network. So, "blockchain technology" has excellent consideration due to its unique qualities such as decentralized network, openness, irreversible data, and cryptography functions. Blockchain technology depends on cryptography hash techniques for safe transmission. For increased security, it transforms the variable size inputs into a constant length hash result. Current cryptographic hash algorithms with digital signatures are only able to access keys up to a size of 256 bytes and have concerns with single node accessibility. It just uses the bits that serve as the key to access the data. This paper proposes the "Revised Elliptic Curve Cryptography Multi-Signature Scheme" (RECC-MSS) for multinode availability to find the nearest path for secure communications with the medical image as keys. Here, the input image key can be converted into an array of data that can be extended up to 512 bytes of size. The performance of the proposed algorithm is analyzed with other cryptography hash functions like Secure Hashing Algorithms (SHAs) such as "SHA224", "SHA256", "SHA384", "SHA512", "SHA3-224", "SHA3-256", "SHA3-384", "SHA3-512", and "Message Digest5" (MD5) by "One-way ANOVA" test in terms of "accuracy", "throughput" and "time complexity". The proposed scheme with ECC achieved the throughput of 17.07 kilobytes per 200 nano seconds, 93.25% of accuracy, 1.5 nanoseconds latency of signature generation, 1.48 nanoseconds latency of signature verification, 1.5 nanoseconds of time complexity with 128 bytes of hash signature. The RECC-MSS achieved the significance of 0.001 for accuracy and 0.002 for time complexity which are less than 0.05. From the statistical analysis, the proposed algorithm has significantly high accuracy, high throughput and less time complexity than other cryptography hash algorithms. [ABSTRACT FROM AUTHOR]

Research on quantum computers has advanced significantly in recent years. If humanity ever creates an effective quantum computer, many of the present public key cryptosystems can be compromised. These cryptosystems are currently found in many commercial products. We have devised solutions that seem to protect us from quantum attacks, but they are unsafe and inefficient for use in everyday life. In the paper, hash-based digital signature techniques are analyzed. A Merkle-tree-based digital signature is assessed. Using a Verkle tree and vector commitments, the paper explores novel ideas. The authors of this article present a unique technology for developing a post-quantum digital signature system using state-of-the-art Verkle tree technology. A Verkle tree, vector commitments, and vector commitments based on lattices for post-quantum features are used for this purpose. The concepts of post-quantum signature design utilizing a Verkle tree are also provided in the paper. [ABSTRACT FROM AUTHOR]

(1) Background: Telemetry units allow the continuous monitoring of vital signs and ECG of patients. Such physiological indicators work as the digital signatures and biomarkers of disease that can aid in detecting abnormalities that appear before cardiac arrests (CAs). This review aims to identify the vital sign abnormalities measured by telemetry systems that most accurately predict CAs. (2) Methods: We conducted a systematic review using PubMed, Embase, Web of Science, and MEDLINE to search studies evaluating telemetry-detected vital signs that preceded in-hospital CAs (IHCAs). (3) Results and Discussion: Out of 45 studies, 9 met the eligibility criteria. Seven studies were case series, and 2 were case controls. Four studies evaluated ECG parameters, and 5 evaluated other physiological indicators such as blood pressure, heart rate, respiratory rate, oxygen saturation, and temperature. Vital sign changes were highly frequent among participants and reached statistical significance compared to control subjects. There was no single vital sign change pattern found in all patients. ECG alarm thresholds may be adjustable to reduce alarm fatigue. Our review was limited by the significant dissimilarities of the studies on methodology and objectives. (4) Conclusions: Evidence confirms that changes in vital signs have the potential for predicting IHCAs. There is no consensus on how to best analyze these digital biomarkers. More rigorous and larger-scale prospective studies are needed to determine the predictive value of telemetry-detected vital signs for IHCAs. [ABSTRACT FROM AUTHOR]

Due to frequent traffic accidents around the world, people often take out car insurance to mitigate their losses and receive compensation in a traffic accident. However, in the existing car insurance claims process, there are problems such as insurance fraud, inability to effectively track and transmit insurance data, cumbersome insurance procedures, and high insurance data storage costs. Since the immutability and traceability features of blockchain technology can prevent data manipulation and trace past data, we have used the Elliptic Curve Digital Signature Algorithm (ECDSA) to sign and encrypt car insurance data, ensuring both data integrity and security. We propose a blockchain and IPFS-based anticounterfeiting and traceable car insurance claims system to improve the above problems. We incorporate the Interplanetary File System (IPFS) to reduce the cost of storing insurance data. This study also attempts to propose an arbitration mechanism in the event of a car insurance dispute. [ABSTRACT FROM AUTHOR]

Blockchain technology provides efficient and secure solutions to various online activities by utilizing a wide range of cryptographic tools. In this article, we survey the existing literature on post-quantum secure digital signatures that possess exotic advanced features and that are crucial cryptographic tools used in the blockchain ecosystem for (1) account management, (2) consensus efficiency, (3) empowering scriptless blockchain, and (4) privacy. The exotic signatures that we particularly focus on in this work are the following: multi-/aggregate, threshold, adaptor, blind, and ring signatures. Herein the term "exotic" refers to signatures with properties that are not just beyond the norm for signatures, e.g., unforgeability, but also imbue new forms of functionalities. Our treatment of such exotic signatures includes discussions on existing challenges and future research directions in the post-quantum space. We hope that this article will help to foster further research to make post-quantum cryptography more accessible so that blockchain systems can be made ready in advance of the approaching quantum threats. [ABSTRACT FROM AUTHOR]

Recently, Thumbur et al. (IEEE Commun Lett 24(8): 1641–1645, 2020) proposed a pairing-free certificateless signature (PF-CLS) scheme for secure communication in resource-constrained devices. Zhan et al. (IEEE Internet of Things Journal, pp 1-1, 2020) proposed a pairing-free certificateless aggregate signature (PF-CLAS) in healthcare wireless medical sensor networks. The authors proved the security of their schemes under the hardness of mathematical problems in the random oracle model respectively. Unfortunately, we find that the above two recent schemes are insecure. By providing concrete attacks, in this work, we show that an attacker with replacing public key ability can easily impersonate other legitimate users to upload some false messages by forging the target users' valid signatures on these messages. As a result, the above two signature schemes PF-CLS and PF-CLAS cannot solve the IoT data authenticity and integrity issues pointed out by them. Moreover, we discuss the reasons for our attacks and provide relevant improvements. [ABSTRACT FROM AUTHOR]

This paper proposes and evaluates a new bipartite post-quantum digital signature protocol based on Winternitz chains and an oracle. Mutually mistrustful Alice and Bob are able to agree and sign a series of documents in a way that makes it impossible (within the assumed security model) to repudiate their signatures. The number of signatures supported by a single public key is still limited, though by a large number. However, the security of the signature scheme is not diminished by repeated application, so when the capacity of a public key is exhausted the last transaction can be used to agree a new key. Some ramifications are discussed, security parameters evaluated and an application area delineated for the proposed concept. [ABSTRACT FROM AUTHOR]

Physically unclonable functions (PUFs) are crucial for enhancing cybersecurity by providing unique, intrinsic identifiers for electronic devices, thus ensuring their authenticity and preventing unauthorized cloning. The SRAM-PUF, characterized by its simple structure and ease of implementation in various scenarios, has gained widespread usage. The soft-decision Reed–Muller (RM) code, an error correction code, is commonly employed in these designs. This paper introduces the design of an RM code soft-decision attack algorithm to reveal its potential security risks. To address this problem, we propose a soft-decision SRAM-PUF structure based on the elliptic curve digital signature algorithm (ECDSA). To improve the processing speed of the proposed secure SRAM-PUF, we propose a custom ECDSA scheme. Further, we also propose a universal architecture for the critical operations in ECDSA, elliptic curve scalar multiplication (ECSM), and elliptic curve double scalar multiplication (ECDSM) based on the differential addition chain (DAC). For ECSMs, iterations can be performed directly; for ECDSMs, a two-dimensional DAC is constructed through precomputation, followed by iterations. Moreover, due to the high similarity of ECSM and ECDSM data paths, this universal architecture saves hardware resources. Our design is implemented on a field-programmable gate array (FPGA) and an application-specific integrated circuit (ASIC) using a Xilinx Virtex-7 and an TSMC 40 nm process. Compared to existing research, our design exhibits a lower bit error rate ( 2.7 × 10 − 10 ) and better area–time performance (3902 slices, 6.615 μ s ECDSM latency). [ABSTRACT FROM AUTHOR]

Security vulnerabilities in the symmetric-key primitives of a cipher can undermine the overall security claims of the cipher. With the rapid advancement of quantum computing in recent years, there is an increasing effort to evaluate the security of symmetric-key cryptography against potential quantum attacks. This paper focuses on analyzing the quantum attack resistance of AIM, a symmetric-key primitive used in the AIMer digital signature scheme. We present the first quantum circuit implementation of AIM and estimate its complexity (such as qubit count, gate count, and circuit depth) with respect to Grover's search algorithm. For Grover's key search, the most important optimization metric is depth, especially when considering parallel search. Our implementation gathers multiple methods for a low-depth quantum circuit of AIM in order to reduce the Toffoli depth and full depth (such as the Karatsuba multiplication and optimization of inner modules;  Mer ,  LinearLayer). [ABSTRACT FROM AUTHOR]

Lattice-based digital signature has become one of the widely recognized post-quantum algorithms because of its simple algebraic operation, rich mathematical foundation and worst-case security, and also an important tool for constructing cryptography. This survey explores lattice-based digital signatures, a promising post-quantum resistant alternative to traditional schemes relying on factoring or discrete logarithm problems, which face increasing risks from quantum computing. The study covers conventional paradigms like Hash-and-Sign and Fiat-Shamir, as well as specialized applications including group, ring, blind, and proxy signatures. It analyzes the versatility and security strengths of lattice-based schemes, providing practical insights. Each chapter summarizes advancements in schemes, identifying emerging trends. We also pinpoint future directions to deploy lattice-based digital signatures including quantum cryptography. [ABSTRACT FROM AUTHOR]

The same individuals can express very different emotions in online social media with respect to face-to-face interactions, partially because of intrinsic limitations of the digital environments and partially because of their algorithmic design, which is optimized to maximize engagement. Such differences become even more pronounced for topics concerning socially sensitive and polarizing issues, such as massive pharmaceutical interventions. Here, we investigate how online emotional responses change during the large-scale COVID-19 vaccination campaign with respect to a baseline in which no specific contentious topic dominates. We show that the online discussions during the pandemic generate a vast spectrum of emotional response compared to the baseline, especially when we take into account the characteristics of the users and the type of information shared in the online platform. Furthermore, we analyze the role of the political orientation of shared news, whose circulation seems to be driven not only by their actual informational content but also by the social need to strengthen one's affiliation to, and positioning within, a specific online community by means of emotionally arousing posts. Our findings stress the importance of better understanding the emotional reactions to contentious topics at scale from digital signatures, while providing a more quantitative assessment of the ongoing online social dynamics to build a faithful picture of offline social implications. [ABSTRACT FROM AUTHOR]

Post-quantum cryptography is considered to provide security against both traditional and quantum computer attacks. Dilithium is a digital signature algorithm that derives its security from the challenge of finding short vectors in lattices. It has been selected as one of the standardizations in the NIST post-quantum cryptography project. Hardware-software co-design is a commonly adopted implementation strategy to address various implementation challenges, including limited resources, high performance, and flexibility requirements. In this study, we investigate using compact instruction set extensions (ISEs) for Dilithium, aiming to improve software efficiency with low hardware overheads. To begin with, we propose tightly coupled accelerators that are deeply integrated into the RISC-V processor. These accelerators target the most computationally demanding components in resource-constrained processors, such as polynomial generation, Number Theoretic Transform (NTT), and modular arithmetic. Next, we design a set of custom instructions that seamlessly integrate with the RISC-V base instruction formats, completing the accelerators in a compact manner. Subsequently, we implement our ISEs in a chip design for the Hummingbird E203 core and conduct performance benchmarks for Dilithium utilizing these ISEs. Additionally, we evaluate the resource consumption of the ISEs on FPGA and ASIC technologies. Compared to the reference software implementation on the RISC-V core, our co-design demonstrates a remarkable speedup factor ranging from 6.95 to 9.96. This significant improvement in performance is achieved by incorporating additional hardware resources, specifically, a 35% increase in LUTs, a 14% increase in FFs, 7 additional DSPs, and no additional RAM. Furthermore, compared to the state-of-the-art approach, our work achieves faster speed performance with a reduced circuit cost. Specifically, the usage of additional LUTs, FFs, and RAMs is reduced by 47.53%, 50.43%, and 100%, respectively. On ASIC technology, our approach demonstrates 12, 412 cell counts. Our co-design provides a better tradeoff implementation on speed performance and circuit overheads. [ABSTRACT FROM AUTHOR]

CRYSTALS-Dilithium and Falcon are digital signature algorithms based on cryptographic lattices, which are considered secure even if large-scale quantum computers will be able to break conventional public-key cryptography. Both schemes have been selected for standardization in the NIST Post-Quantum competition. In this work, we present a RISC-V HW/SW codesign that aims to combine the advantages of software and hardware implementations, i.e., flexibility and performance. It shows the use of flexible hardware accelerators, which have been previously used for Public-Key Encryption (PKE) and Key-Encapsulation Mechanism (KEM), for Post-Quantum signatures. It is optimized for Dilithium as a generic signature scheme but also accelerates applications that require fast verification of Falcon's compact signatures. We provide a comparison with previous works showing that for Dilithium and Falcon, cycle counts are significantly reduced, such that our design is faster than previous software implementations or other HW/SW codesigns. In addition to that, we present a compact Globalfoundries 22nm ASIC design that runs at 800 MHz. By using hardware acceleration, energy consumption for Dilithium is reduced by up to 92.2%, and up to 67.5% for Falcon's signature verification. [ABSTRACT FROM AUTHOR]

With the development of large-scale quantum computers, the current landscape of asymmetric cryptographic algorithms will change dramatically. Today's standards like RSA, DSA, and ElGamal will no longer provide sufficient security against quantum attackers and need to be replaced with novel algorithms. In the face of these developments, NIST has already started a standardization process for new Key Encapsulation Mechanisms (KEMs) and Digital Signatures (DSs). Moreover, NIST has recommended the two stateful Hash-Based Signatures (HBSs) schemes XMSS and LMS for use in devices with a long expected lifetime and limited capabilities for maintenance. Both schemes are also standardized by the IETF. In this work, we present the first agile hardware implementation that supports both LMS and XMSS. Our design can instantiate either LMS, XMSS, or both schemes using a simple configuration setting. Leveraging the vast similarities of the two schemes, the hardware utilization of the agile design increases by 20% in LUTs and only 3% in Flip Flops (FFs) over a standalone XMSS implementation. Furthermore, our approach can easily be configured with an arbitrary number of hash cores and accelerators for the one-time signatures for different application scenarios. We evaluate our implementation on the Xilinx Artix-7 FPGA platform, which is the recommended target for PQC implementations by NIST. We explore potential tradeoffs in the design space and compare our results to previous work in this field. [ABSTRACT FROM AUTHOR]

Elliptic curve (EC) cryptography supplies an efficient, secure, and lightweight method for executing computer cryptographic protocols. Its widespread use in various applications, including secure communications, digital signatures, and key agreement protocols, highlights its importance in modern computing. Moreover, EC-based image encryption is gaining popularity in cryptography as it offers strong protection with a relatively smaller key size than other famous cryptosystems. Inspired by this, we proposed a novel image encryption scheme that leverages ECs over a binary extension field (BEF). This approach also reduces computational workload using EC over BEF instead of large primes. Also, BEF can represent large numbers in a compact form, which is helpful in applications that require efficient data storage and transmission. Our scheme involves three main steps. Initially, we utilize points of an EC over a BEF and a piecewise function to mask the plain image. Next, to introduce a high level of confusion in the plain text, we create a substitution box (S-box) based on the EC and operation of BEF of order 256, which is then used to permute the pixels of the masked image. Finally, we generate pseudo-random numbers (PRNs) using EC coordinates and BEF characteristics to create diffusion in the image and obtain a cipher image. In addition, we accomplished computational experiments demonstrating that our proposed cryptosystem provides excellent security against linear, differential, and statistical attacks compared to existing cryptosystems. [ABSTRACT FROM AUTHOR]