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Background: Stroke patients usually experience damage to multiple functions and a long rehabilitation period. Hence, there is a large volume of patient clinical information. It thus takes a long time for clinicians to identify the patient’s information and essential pieces of information may be overlooked. To solve this, we stored the essential clinical information of stroke patients in a blockchain and implemented the blockchain technology using the Java programming language.Methods: We created a mini blockchain to store the medical information of patients using the Java programming language.Results: After generating a unique pair of public/private keys for identity verification, a patient’s identity is verified by applying the Elliptic Curve Digital Signature Algorithm based on the generated keys. When the identity verification is complete, new medical data are stored in the transaction list and the generated transaction is verified. When verification is completed normally, the block hash value is derived using the transaction value and the hash value of the previous block. The hash value of the previous block is then stored in the generated block to interconnect the blocks. Conclusion: We demonstrated that blockchain can be used to store and deliver the patient information of stroke patients. It may be difficult to directly implement the code that we developed in the medical field, but it can serve as a starting point for the creation of a blockchain system to be used in the field.

The privacy and utility are treated as a major factor in influencing the role of data privacy preservation in cloud environments. There exists a trade-off between these two factors, where one factor should compromise its functionality over the other. It is hence necessary to maintain both utility and privacy for a data offloaded or accessed across cloud computing environment. In this paper, we develop a utility privacy model that established utility using Deep Adaptive Clustering (DAC) and privacy using Elliptic Curve Digital Signature Algorithm (ECDSA). The utility is performed using clustering of the input datasets using DAC and the privacy is maintained using ECDSA. The simulation is conducted on specific datasets to test the efficacy of the model and the results shows improved accuracy on clustering, and efficient privacy metrics than existing methods.

Over the years, digital signature algorithms such as Rivest–Shamir–Adleman (RSA) and elliptic curve digital signature algorithm (ECDSA) are the commonly used algorithms to secure data in the public key infrastructure and other computing devices. The security notions of these algorithms relied on the difficulty of an attacker to solve the integer factorization problem used in RSA and the discrete logarithm problem in ECDSA. With the advent of quantum computers and the development of quantum algorithms, the security of data by cryptosystems are not secure. In this research, the authors carried out the review analysis of two classical algorithms (RSA, ECDSA) and hash-based signature schemes; Winternitz one time signature (W-OTS) and Merkle signature (MSS), their security strength, efficiency in terms of key generation time, signature generation and verification time. Two approaches were used: the algorithms prove of concepts which involved practical implementation of the selected hash-based signature schemes and the classical algorithms. From the results obtained and displayed in Table 8, the signature generation time of RSA and ECDSA were 0.08 ms and 0.02 ms as compared with MSS which has high values more than the RSA and ECDSA and it is 2.40 ms. The results showed that the two classical algorithms perform better in terms of the efficiency in key generation time, signature generation and verification time. However, the key generation time, signature generation and verification time increases when the key length increases. The security of the classical algorithms improved when the key length increase. Evidently an increase in signature verification time could lead to denial of service attack and quantum computer related attacks. The hash-based signature schemes in this research were considered to be the best alternative algorithms suitable for public key infrastructures considering the security properties exhibited by them. Their security depends on the hash function used and the collision resistant properties of the underlying hash function. Also the hash-based signature schemes are forward secure and uses collision resistant cryptographic hash function and a pseudorandom number generator as illustrated in Table 10.

This paper try to introduce the advantages and disadvantages of the Elliptical Curve Digital Signature Algorithm that could be put in consideration for future usage through applications and future scalability depending on improvement levels of elliptical curve Digital Signature Algorithm starting from The elliptical Curve Cryptography that it was extracted from till showing, elliptical curve Digital Signature Algorithm's security power, performance quality, memory usage rate, applications, challenges, and last improvement. To help in the future in evading some problems like forgery, worse usage of memory because of big sized keys that cause the need for high processing power that reduces the performance quality, and considering it as a level in a new algorithm to reduce the tries of attacking and hacking specific messages between specific parties, after explaining the Elliptical Curve Cryptography and how the scientists reached from the Elliptical Curve Cryptography to the Elliptical Curve Digital Signature Algorithm and why they developed Elliptical Curve Digital Signature Algorithm, the paper will explain its advantages and disadvantages of the Elliptical Curve Digital Signature Algorithm, then the paper will explain what is the differences happen in a new type of the Elliptical Curve Digital Signature Algorithm called Multiple Elliptical Curve Digital Signature Algorithm, trying to show what is the improvement stages was happened in the Elliptical Curve Digital Signature Algorithm, how that affected the nowadays applications, and how that participated in improving the security performance and increasing the security strength, there fore what was included in the paper could be used as a nucleus for more and more improving of the Elliptical Curve Digital Signature Algorithm, and evading its defects.&nbsp

Internet of Things (IoT) has received attention recently, featuring tremendous applications. Due to the lack of authentication, popular IoT applications are prone to various attacks. However, because of resource limitation and heterogeneous characteristics of IoT applications, the cryptographic algorithms may fail to be universal adopted and thus, it is challenging to defend against these attacks. In this paper, we proposed NOMOP-ECDSA, a lightweight Elliptic Curve Digital Signature Algorithm for IoT applications, which can address the aforementioned challenge. Our idea is that the resource-consuming operations can be replaced with other basic operations, and therefore, achieve better performance. As a demonstration, we also proposed a mutual authentication protocol for smart cards. In terms of security and efficiency, systematic analysis is performed to validate our NOMOP-ECDSA and protocol.

The Internet of Things (IoT) becomes a leading field of computer science, which simplifies the life of human beings. The IoT, devices can interconnect and communicate with each other, in a fully autonomous mode. This autonomy has made the IoT network vulnerable to various security threats. However, due to this autonomy, there is a strong need for reliable security and storage mechanism for authentication to exchange data between IoT devices. To solve this problem, we propose an efficient method known as SCAB-IoTA, which ensures identification and authentication of IoT devices and also provides secure communication in the open environment. Along with authentication and secure communication, the scheme also ensures data integrity. SCAB-IoTA used the blockchain and hybrid cryptosystem (the combination of Advanced Encryption Standard (AES) and Elliptic Curve Digital Signature Algorithm (ECDSA) cryptographic techniques) to enhance the security of IoT applications to prevent various attacks along with less computational, and storage overhead. Furthermore, we have a secure cluster of IoT devices based on angular distance (AD), so that devices can securely communicate without any interruption. A secure and robust trust mechanism has employed to build these clusters, where each IoT device has to authenticate itself before joining the cluster. The obtained results satisfy the IoT security requirements with 60% reduced computation, storage and communication cost compared with state-of-the-art methods. The security analysis illustrates that SCAB-IoTA withstands against various cyberattacks such as impersonation, message replay, man-in-the-middle, and botnet attacks.

The sensing-as-a-service (SaaS) model has been explored to address the challenge of intractability of managing a large number of sensors faced by future smart cities. However, how to effectively share sensor data without compromising confidentiality, privacy protection, and fair trading without third parties is one of critical issues that must be solved in the SaaS in smart cities. While blockchain shows promise in solving these issues, the existing blockchain-based data sharing (BBDS) systems are difficult to apply to SaaS in smart cities because of many unresolved issues such as requiring a customized blockchain, huge storage, communication and computation costs, and dependence on a third party to achieve fair trading. We propose a BBDS system model with its security requirements before we present a concrete construction by combining -protocol, Paillier encryption scheme, and any secure symmetrical encryption and signature schemes. To demonstrate the utility of our proposed BBDS system, we present a security analysis and compare our system with other solutions. We implement the prototype in Remix to analyze the gas cost, and we conduct experiments to evaluate the communication and computation costs of the BBDS system using symmetric encryption (advanced encryption standard (AES)) and a signature scheme (elliptic curve digital signature algorithm (ECDSA)).

Lattice attacks can compromise the security of encryption algorithms used in blockchain networks, allowing attackers to tamper with transaction records, steal private keys, and execute other forms of attacks. With symmetric encryption, both parties can encrypt and decrypt messages using the same key. Lattice attacks on digital signature algorithms (ECDSA) involve forming a basis and setting a target vector from signatures, then solving the closest vector problem (CVP) or shortest vector problem (SVP) in the generated lattice to obtain the private key. Prior research focused on obtaining leakage information from the signature’s random nonce to facilitate a CVP or SVP solution. This study establishes a clear boundary for a successful ECDSA attack and introduces a “double basis” lattice version that expands the boundary or reduces the necessary signatures by nearly half with the same lattice rank. To approach the boundary, a heuristic strategy is employed to shift the target vector in different directions with a feasible step size, using tests on the Trusted Platform Module (TPM) 2.0 ECDSA. The distance from the closest moved target vector to the boundary is reduced by a ratio of 424 to 179 to the minimal length of orthogonal vectors in the formed basis. Experimental results show that moving attempts in two directions with the original basis and 84 signatures take approximately 247.7 s on the experiment computer.

In data communication systems, digital signatures are a form of electronic signature security services based on the Elliptic Curve Digital Signature Algorithm (ECDSA) which are considered resistant to certain types of attacks. Attacks on digital signature schemes aim to fake a signature or are called forgery which is said to be successful if the key pair and signature generated by the attacker are accepted by the verifier. Mathematical schemes used to prove the authenticity of messages or digital documents or guarantees that the data and information actually come from the correct source. ECDSA-based digital signatures rely on discrete logarithmic problems as the basis for mathematical calculations. Q = kP where Q and P are the points of the elliptic curve in the finite field or and k is a positive integer number. The hash function generated from the algorithm process is then encoded (encrypted) with an asymmetric key cryptographic algorithm. In this work use p = 149 to encrypt plain text by converting the original message using dots on a curve with the help of Python programs.

White-box attack context assumes that the running environments of algorithms are visible and modifiable. Algorithms that can resist the white-box attack context are called white-box cryptography. The elliptic curve digital signature algorithm (ECDSA) is one of the most widely used digital signature algorithms which can provide integrity, authenticity, and nonrepudiation. Since the private key in the classical ECDSA is plaintext, it is easy for attackers to obtain the private key. To increase the security of the private key under the white-box attack context, this article presents an algorithm for the white-box implementation of ECDSA. It uses the lookup table technology and the “cloud plus side” mode to protect the private key. The residue number system (RNS) theory is used to reduce the size of storage. Moreover, the article analyzes the security of the proposed algorithm against an exhaustive search attack, a random number attack, a code lifting attack, and so on. The efficiency of the proposed scheme is compared with that of the classical ECDSA through experiments.

Cross-border data sharing for knowledge generation is a challenging research direction since an application may access personal data stored in countries different from the one where the application is accessed from. In this article, we propose a cross-border data sharing platform where a global cloud is built atop multiple security gateways that are set up in different countries. Once an application requests access to data from a particular country or region, the global cloud collects the data stored in local data hubs through that region's security gateway. While transferring the data to the global cloud, the security gateway records this transfer information on a blockchain maintained by the global cloud. When an application reports any misbehavior (e.g., providing wrong data type or incorrect data) against a security gateway, the global cloud verifies the claim by auditing the blockchain and punishes the misbehaving security gateway if the claim is true. In the case of false misbehavior report, the application itself will be punished by the global cloud. Thus, our platform provides an accountable data sharing function using blockchain that relies on a relaxed trust assumption on the data providers. We include five algorithms to handle data access request, data sharing, blockchain transaction, detecting, and punishing misbehaving entities. In the algorithms, we also introduce how the transaction takes place in the platform. Thus, the proposed platform is able to handle misbehaving data sender, data receiver, or any entity participating in the platform. We analyze our platform empirically by showing different graphs, which have been generated by a number of experiments on blockchain environment. We also delineate how the multilayer of signature (Elliptic Curve Digital Signature Algorithm) acts in our platform.

To study the security performance of the Internet of multimedia things on the privacy protection of user identity, behavior trajectory, and preference under the new information technology industry wave, in this study, aiming at the problems of the sharing of Internet of things perception data and the exposure of users’ privacy information, the Anonymous Batch Authentication Scheme (ABAH) for privacy protection is designed. Hash-based Message Authentication Code is used to cancel the list-checking process and analyze its security performance. Compared with the methods of elliptic curve digital signature algorithm, Bayes least-square method, identity-based bulk verification, anonymous batch authentication and key protocol, conditional privacy authentication scheme, and expert message authentication protocol, the transmission delay, packet loss rate, and computation cost are studied without considering the undo list and during the undo check. The results show that with the increase of information size, the transmission delay and packet loss rate also increase, and the transmission delay of ABAH increases by about 15%, while the correlation between speed and transmission delay is small. In the case of the same amount of validation information, ABAH has the highest validation efficiency, and it still has an efficient validation effect in the case of invalid information. The message packet loss rate for ABAH is always 0 when the undo check validation overhead is considered. It can be found that ABAH can avoid the communication overhead and privacy leakage caused by the revocation list, ensure the integrity of batch verification information, meet the security performance of the vehicular ad hoc network under the Internet of Things, and protect the privacy of users from being disclosed.

The digital signature scheme, which underpins most of the existing distributed ledgers, is generally based on non-quantum-resilient algorithms (e.g. elliptic curve digital signature algorithm). This highlights the need for quantum-secure signature schemes in future distributed ledgers (and other products). Therefore, in this paper, we propose a novel quantum-secure digital signature scheme designed specifically for cryptocurrencies. Our proposed scheme is a hash-based signature scheme, which is a variant of Winternitz-one time signature scheme. A comparison of the proposed scheme and two other competing quantum-secure cryptocurrencies (IoTA and QRL) reveals that our scheme respectively achieves 59% and 24% reductions in signature lengths without compromising the level of security. A salient feature of the proposed approach is that, unlike the previously proposed variants of Winternitz scheme, we avoid the need for any expensive computation. In addition, we formally model the classical cryptocurrency and the proposed quantum-secure cryptocurrency using high-level Petri-nets, which allows the implementer to understand their workings in the presence of a quantum attacker. Furthermore, we also provide formal security proof in the random oracle model.

Due to the abundant marine resources, smart ocean has attracted much attention of the government, industry, and academy. The Internet-of-Things (IoT) architectures for smart ocean have been proposed to collect various of data from the ocean, thereby assisting environmental protection, military reconnaissance, and so on. However, few researchers have paid attention to the security and privacy issues of data collection and transmission. In this article, for the unreliable underwater environment, we present a secure, efficient, and complete data collection, and transmission and storage scheme for IoT in smart ocean. Especially, to prolong the lifetime of the underwater node, two novel data compression algorithms [lossy data compression algorithm (LCA) and lossless data compression algorithm (NLCA)] are also proposed. Moreover, due to the vulnerability of underwater nodes, we also propose a corresponding IoT framework and data collection pattern to resist the single point failure attack. Besides, to guarantee the confidentiality, reliability, and integrity of transmitting data, Elliptic Curve-ElGamal (EC-ElGamal) and elliptic curve digital signature algorithm (ECDSA) are employed. The consensus algorithm and blacklisting mechanism are also employed to detect and address failure or malicious nodes. Finally, the security analysis demonstrates that our scheme is able to resist many typical attacks for underwater nodes, such as manipulation attacks, Distributed Denial-of-Service (DDoS) attacks, malicious node injection attacks, and so on. Additionally, relevant experimental results show that the scheme is feasibility and efficiency.

The upcoming quantum era is believed to be an end for the elliptic curve digital signature algorithm (ECDSA) and other number-theoretic digital signature schemes. Hence, the technologies which incorporate ECDSA would be at risk once quantum computers are available at large scale. Distributed ledger technology is one of the potential victims of powerful quantum computers. Fortunately, post-quantum digital signature schemes are already available. Hash-based digital signatures (HBS) schemes due to their simplicity and efficiency have gained tremendous attention from the research community. However, large size of key and signature are the major drawbacks of HBS schemes. This paper proposes a compact and efficient HBS scheme “Smart Digital Signatures” (SDS), which is closer to an existing popular HBS scheme, XMSS. SDS incorporates a novel one-time signature (OTS) scheme in XMSS, namely SDS-OTS. Furthermore, SDS uses a slightly modified version of the key compression tree as compared to XMSS. We have compared SDS with XMSS-WOTS and XMSS-WOTS + . The results reveal a significant reduction in hash tree construction time compared to XMSS, and key and signature sizes compared to WOTS and WOTS + . Finally, we have also proposed a model for incorporating SDS into a distributed ledger, with the help of High-Level Petri-nets.

Proof of stake (PoS), aiming at replacing Proof of work (PoW) in blockchain consensus, has drawn great attention from academia and industry. We present "Baguena", a novel PoS protocol for public blockchain with high practicality and security. It uses a special designed algorithm with properties of uniqueness and anonymity for leader selection, and uses the longest chain rule for chain selection. Besides, entropy is introduced to prevent manipulation of leader selection process by simulating a random beacon based on Publicly verifiable secret sharing (PVSS) and threshold signature with only a linear number of exponentiations. We analyze the protocol's security by a threat model and design a robust delegation mechanism based on triple Elliptic curve digital signature algorithm (ECDSA) proxy signature. We implement Baguena and evaluate its performance on 100 Amazon EC2 virtual machines simulating 50k users, which shows that Baguena confirms transactions in 2 minutes, achieves 2.16x of Algorand's throughput and 6.95x of Ouroboros' throughput.

We present our discovery of a group of side-channel vulnerabilities in implementations of the ECDSA signature algorithm in a widely used Atmel AT90SC FIPS 140-2 certified smartcard chip and five cryptographic libraries (libgcrypt, wolfSSL, MatrixSSL, SunEC/OpenJDK/Oracle JDK, Crypto++). Vulnerable implementations leak the bit-length of the scalar used in scalar multiplication via timing. Using leaked bit-length, we mount a lattice attack on a 256-bit curve, after observing enough signing operations. We propose two new methods to recover the full private key requiring just 500 signatures for simulated leakage data, 1200 for real cryptographic library data, and 2100 for smartcard data. The number of signatures needed for a successful attack depends on the chosen method and its parameters as well as on the noise profile, influenced by the type of leakage and used computation platform. We use the set of vulnerabilities reported in this paper, together with the recently published TPM-FAIL vulnerability [MSE+20] as a basis for real-world benchmark datasets to systematically compare our newly proposed methods and all previously published applicable lattice-based key recovery methods. The resulting exhaustive comparison highlights the methods’ sensitivity to its proper parametrization and demonstrates that our methods are more efficient in most cases. For the TPM-FAIL dataset, we decreased the number of required signatures from approximately 40 000 to mere 900.

The disclosure of personal and private information is one of the main challenges of the Internet of Medical Things (IoMT). Most IoMT-based services, applications, and platforms follow a common architecture where wearables or other medical devices capture data that are forwarded to the cloud. In this scenario, edge computing brings new opportunities to enhance the operation of IoMT. However, despite the benefits, the inherent characteristics of edge computing require countermeasures to address the security and privacy issues that IoMT gives rise to. The restrictions of IoT devices in terms of battery, memory, hardware resources, or computing capabilities have led to a common agreement for the use of elliptic curve cryptography (ECC) with hardware or software implementations. As an example, the elliptic curve digital signature algorithm (ECDSA) is widely used by IoT devices to compute digital signatures. On the other hand, it is well known that dual signature has been an effective method to provide consumer privacy in classic e-commerce services. This article joins both approaches. It presents a novel solution to enhanced security and the preservation of data privacy in communications between IoMT devices and the cloud via edge computing devices. While data source anonymity is achieved from the cloud perspective, integrity and origin authentication of the collected data is also provided. In addition, computational requirements and complexity are kept to a minimum.

Cache-timing attacks are serious security threats that exploit cache memories to steal secret information. We believe that the identification of a sequence of function calls from cache-timing data measurements is not a trivial step when building an attack. We present a recurrent neural network model able to automatically retrieve a sequence of operations from cache timings. Inspired from natural language processing, our model is able to learn on partially labelled data. We use the model to unfold an end-to-end automated attack on OpenSSL ECDSA on the secp256k1 curve. Our attack is able to extract the 256 bits of the secret key by automatic analysis of about 2400 traces without any human processing.

International audience; The security of the Bitcoin cryptocurrency system depends on the Koblitz curve secp256k1 combined with the digital signature ECDSA and the hash function SHA-256. In this paper, we show that the security of Bitcoin with ECDSA and secp256k1 is not optimal and present a detailed study of the efficiency of Bitcoin with the digital signature algorithm Ed25519 combined with the twisted Edwards curve CurveEd25519 and the hash function SHA-512. We show that Bitcoin is more secure and more efficient with the digital signature algorithm Ed25519 and the twisted Edwards curve CurveEd25519. Subject Classifications: 94A60

Elliptic curve cryptography (ECC) has been the main choice for the security experts from some time now. As the IoT has enveloped the world around us; ECC has became more popular as security solutio...

Kleptography is the study of pilfering secure data secretly and subliminally. The concept of inserting backdoors was introduced two decades ago by Young and Yung. However, still it is a serious threat for modern cryptography. Different studies have proved that exploiting implementation errors of cryptographic algorithms needs less effort as compared to attacking its mathematical structure. Inserting the backdoor modifies the standard method of generating public and private key pairs in such away that the public information is meaningful for the attacker. This paper presents the kleptographic attack on cryptographic algorithm based on Elliptic curves. We show the technique of implementing backdoor against Edwards-curve Digital Signature Algorithm, Elliptic curve Diffie-Hellman key exchange scheme, Elliptic curve Digital Signature Algorithm, Elliptic curve Integrated Encryption Scheme, Elliptic curve ElGamal Encryption and Elliptic curve Qu-Vanstone implicit certificate scheme. In practical approach, backdoors are inserted in such a way that their identification is impossible by analyzing the output of an algorithm. Detection of kleptographic implementation is a complex task and very few studies can be found in this direction. We have explored the possibility of detection of malicious code inside the Elliptic curve based algorithms by using the idea of running time analysis. We have shown that by implementing strong Secretly Embedded Trapdoor with Universal Protection (SETUP) attack against Elliptic curve based algorithms, one can detect the presence of backdoor by analyzing the time difference in execution of an honest vs malicious version of code. We also modified the backdoor insertion mechanism in Edwards-curve Digital Signature Algorithm that results in negligible time difference making it impossible for the user to detect backdoor presence.

Bitcoin security draws more and more attention recently. One of Bitcoin vulnerabilities is caused by ECDSA weak randomness. A random number is not cryptographically secure, which leads to private key leakage and even fund theft. This security problem has been well known in Bitcoin community and fixed by applying RFC 6979 update in 2013. In this paper, we systematically revisit the cases where random numbers are reused and evaluate them based on practical Bitcoin transactions. After analyzing Bitcoin transaction dataset from January 2009 to July 2017, we find that there are still approximately 0.48 percent of transactions involving this vulnerability, and 1331 private keys have been compromised. In addition, the transactions related to some involved addresses have a common pattern, which gives us a clue that a spam transaction attack may take advantage of ECDSA weak randomness. We also examine mainstream Bitcoin software wallets to check whether they are susceptible to ECDSA weak randomness. Even the result is quite optimistic, an example that one of the influenced addresses leaked in April 2014 is still in use again in August 2017 reflects that the severity of ECDSA weak randomness may not be paid enough attention even after its discovery and solution in 2013.

An escrow protocol for Bitcoin allows fair trading using bitcoins. To ensure fairness, the existing proposals made various trade-offs between trust, privacy, and efficiency. In this work, we evaluate the existing escrow protocols for cryptocurrency and propose a practical escrow protocol for Bitcoin that is: (a) computationally efficient; (b) round efficient; and (c) privacy-preserving. The core component of our escrow protocol for Bitcoin is a new verifiably encrypted ECDSA scheme, which may be of independent interest. Furthermore, we implement the escrow protocol for Bitcoin in Bitcoin mainnet, demonstrating the feasibility of our protocol.

The article describes the main trends in the field of intellectualization of transport systems and mobility. The possibility of using the Blockchain technology in transport systems is considered. The article proposes to use Blockchain technology for increasing cybersecurity through the creation of a safe and reliable system for sending parameters of the current state of each vehicle using the signals of neighboring vehicles. The authors have developed a tracking system for car actions using the Blockchain system based on the Exonum platform. Mathematical foundations of this system are presented in the article. Data input and confirmation of their acceptance of the transaction is carried out using an Elliptic Curve Digital Signature Algorithm (ECDSA). ECDSA security is related to the complexity of the private key search task described in the article. This largely relates to the management of large-scale systems, such as transport system. Failure to follow simple rules and recommendations can lead to serious consequences, such as road accidents and congestion. Therefore, the proposed system can assist in making decisions with autonomous cars and in investigating crimes as well as traffic offences.

Two-party ECDSA signatures have received much attention due to their widespread deployment in cryptocurrencies. Depending on whether or not the message is required, we could divide two-party signing into two different phases, namely, offline and online. Ideally, the online phase should be made as lightweight as possible. At the same time, the cost of the offline phase should remain similar to that of a normal signature generation. However, the existing two-party protocols of ECDSA are not optimal: either their online phase requires decryption of a ciphertext, or their offline phase needs at least two executions of multiplicative-to-additive conversion which dominates the overall complexity. This paper proposes an online-friendly two-party ECDSA with a lightweight online phase and a single multiplicative-to-additive function in the offline phase. It is constructed by a novel design of a re-sharing of the secret key and a linear sharing of the nonce. Our scheme significantly improves previous protocols based on either oblivious transfer or homomorphic encryption. We implement our scheme and show that it outperforms prior online-friendly schemes (i.e., those have lightweight online cost) by a factor of roughly 2 to 9 in both communication and computation. Furthermore, our two-party scheme could be easily extended to the 2-out-of-n threshold ECDSA.

In many cryptocurrencies, the problem of key management has become one of the most fundamental security challenges. Typically, keys are kept in designated schemes called wallets, whose main purpose is to store these keys securely. One such system is the BIP32 wallet (Bitcoin Improvement Proposal 32), which since its introduction in 2012 has been adopted by countless Bitcoin users and is one of the most frequently used wallet system today. Surprisingly, very little is known about the concrete security properties offered by this system. In this work, we propose the first formal analysis of the BIP32 system in its entirety and without any modification. Building on the recent work of Das et al. (CCS '19), we put forth a formal model for hierarchical deterministic wallet systems (such as BIP32) and give a security reduction in this model from the existential unforgeability of the ECDSA signature algorithm that is used in BIP32. We conclude by giving concrete security parameter estimates achieved by the BIP32 standard, and show that by moving to an alternative key derivation method we can achieve a tighter reduction offering an additional 20 bits of security (111 vs. 91 bits of security) at no additional costs.

This paper analyzes candidate schemes for PPP/PPP-RTK data authentication. Data authentication asymmetric schemes are proposed based on existing standards and compatible with GNSS messages. Postquantum cryptographic signatures are also reviewed and discussed. Two schemes are selected for analysis: DS (digital signature), based on ECDSA, and DD (delayed-disclosure), based on a hybrid scheme using the TESLA protocol. An implementation of each of them is described in detail for both Galileo HAS (High Accuracy Service), and QZSS (Quasi-Zenith Satellite System) CLAS (Centimeter-Level Accuracy Service). The performance of the schemes in terms of time to receive the corrections message, and increase in the age of data (AOD) due to authentication, is analyzed. The analysis is complemented by a review of the CPU consumption at receiver level.

Herein we delineate a complete Satellite-Based Augmentation System (“SBAS”) authentication scheme, including over-the-air re-keying (“OTAR”), that uses Elliptic Curve Digital Signature Algorithm (“ECDSA”) and Timed Efficient Stream Loss Tolerant Authentication (“TESLA”) without using the Quadrature (“Q”) channel. This scheme appends two new message types (”MT”) to the SBAS scheduler without overburdening the SBAS message schedule. We take special care to make our scheme (1) meet appropriate security requirements to prevent and deter spoofing; (2) compatible with existing cryptographic standards; (3) flexible, expandable, and future proof to different cryptographic and implementation schemes; and (4) backward compatible with legacy receivers. The scheme accommodates a diverse set of features, including authenticating core-constellation ephemerides. The scheme requires loose time synchronization between the receiver and the provider, and we assert reasonable mitigation strategies to prevent attacks to that assumption. This work also discusses the SBAS provider and receiver machine state and startup, including aircraft that traverse differing SBAS coverage areas. We test our scheme with existing SBAS simulation and analysis tools to show negligible effects on SBAS availability and continuity requirements.

ECDSA is a standard digital signature scheme that is widely used in TLS, Bitcoin and elsewhere. Unlike other schemes like RSA, Schnorr signatures and more, it is particularly hard to construct efficient threshold signature protocols for ECDSA (and DSA). As a result, the best-known protocols today for secure distributed ECDSA require running heavy zero-knowledge proofs and computing many large-modulus exponentiations for every signing operation. In this paper, we consider the specific case of two parties (and thus no honest majority) and construct a protocol that is approximately two orders of magnitude faster than the previous best. Concretely, our protocol achieves good performance, with a single signing operation for curve P-256 taking approximately 37 ms between two standard machine types in Azure (utilizing a single core only). Our protocol is proven secure for sequential composition under standard assumptions using a game-based definition. In addition, we prove security by simulation under a plausible yet non-standard assumption regarding Paillier. We show that partial concurrency (where if one execution aborts, then all need to abort) can also be achieved.

The blockchain-enabled internet of medical things (IoMT) is an emerging paradigm that could provide strong trust establishment and ensure the traceability of data sharing in the IoMT networks. One of the fundamental building blocks for Blockchain is Elliptic Curve Digital Signature Algorithm (ECDSA). Nevertheless, when processing a large number of transactions, the verification of multiple signatures will incur cumbersome overhead to the nodes in Blockchain. Although batch verification is able to provide a promising approach that verifies multiple signatures simultaneously and efficiently, the upper bound of batch size is limited to small-scale and the efficiency will drop rapidly as the batch size grows in the state-of-the-art ECDSA batch schemes. Meanwhile, most of the existing researches only focus on improving the efficiency of batch verification algorithms in various cryptosystem while ignoring the identification of invalid signatures, which could cause severe performance degradation when the batch verification fails. Motivated by these observations, this paper proposes an efficient and large-scale batch verification scheme with group testing technology based on ECDSA. The application of the presented protocols in Bitcoin and Hyperledger Fabric has been analyzed as supportive and effective. When the batch verification returns a false result, we utilize group testing technology to improve the efficiency of identifying invalid signatures. Comprehensive simulation results demonstrate that our protocol outperforms the related ECDSA batch verification schemes.

The Wireless Sensor Network (WSN) has an evolving technology and is able to be used in critical situation such as commercial applications like traffic surveillance, buildings, smart homes and habitat monitoring, etc. One of the biggest challenges today for wireless sensor networks is security. Wireless Sensor Networks (WSN) security models required the following services like integrity and authentication and confidentiality. A well-designed cryptographic algorithm is the secret to developing a riskless WSN scheme in order to fulfil the requirement for sensor nodes with less resource and low power consumption. Public-key cryptography algorithm, namely elliptical curve cryptography (ECC) & elliptic curve digital signature algorithm (ECDSA), have attracted interest from the many researchers in various institutions because of the security and high performance of these algorithms. Algorithms based on the elliptical curve (EC) have proved computationally efficient and provide more security in comparison to traditional crypto-algorithms in the specified key size. ECDSA is first successful ECC- based algorithm. This paper includes descriptions of ECDSA using the SHA-l. We analyse and propose a improve ECDSA algorithm. The main objective of this improved algorithm is to be provide more security as compared to previous algorithm.

Cloud computing provides its clients with on-demand resources, such as storage and performance. The idea behind cloud computing is sharing of resources. With growth of cloud computing, the risks of security and privacy are arising. Also, the cloud resources are not secure against quantum computers, as quantum computing threatens the best security controls implemented today, that include ECC (Elliptic Curve Cryptography), RSA, DSA (Digital Signature Algorithm) and ECDSA (Elliptic Curve Digital Signature Algorithm). Fortunately, there are quantum-safe digital signatures called Hash-based Signatures, which can also protect integrity, authentication and privacy on the cloud. In this work, a hash-based digital signature scheme called WOTS is implemented to avoid security risks imposed by quantum computing on cloud computing. The implementation is carried out in CloudSim simulator. Apart from achieving quantum safety, the results show that our proposed solution is computationally cost effective.

In telemedicine applications, sensitive and private patients' information is collected and transmitted via a telecommunication system. To assure the security services of the exchanged medical images, improved cryptographic algorithms should be designed to protect private information against attacks. In this paper, we propose an efficient cryptosystem for medical image encryption and authentication. The cryptosystem is an Improved Advanced Encryption Standard (IAES) - Elliptic Curve Digital Signature Algorithm (ECDSA) hybrid scheme that uses symmetric and asymmetric approaches. The first one is used to encrypting the image. The second one is used to encrypting the initial secret key and owner's signature that permit authentication. The implementation on a Cyclone III FPGA uses 18.594 of total logic elements, 17.820 of total combinatorial functions, and 131.616 of total memory. It runs at a frequency of 147.16 MHz, consumes 171.16 mW and can achieve excellent throughput of 1.71 Gb / s. Results prove that the proposed cipher framework is appropriate for embedded systems respecting both real-time performance and resources constrained. The security analysis is successfully performed and experimental results prove that the suggested technique provides the basis of cryptography.

In recent decades, broad range of Internet of Things (IoT) technologies are deployed such as machine to machine communication, Internet Technologies (IT), robots, smart devices, and wireless sensor networks. IoT is a spectacular technology in the modern world of IT in which the objects can do data transmission and connect using the intranet or internet networks. Data security and privacy is one of the top most challenging issue where several researchers are showing interest that to especially in healthcare domain. For this reason, a hybrid combination of Elliptic Curve Digital Signature Algorithm (ECDSA), Rivest Cipher 4 (RC4), and Secure Hash Algorithm (SHA-256) is proposed for protecting the reliable data which is transmitted from the IoT based healthcare systems. In the proposed model, the ECDSA is used for improving the RC4 in which the encryption of key is processed by ECDSA for performing the XOR operation in RC4. Furthermore, the security is ensured by transforming the incoming data using the SHA-256 technique. Experimental results show that the proposed model outperforms for 10 MB of data in terms of encryption time that obtained as 631 ms, decryption time is 616 ms, and throughput obtained by the proposed models is 11.71 MB/ms when compared with other existing techniques such as ECC+3DES+SHA-256, RC4+AES+SHA-256, and ECC+RC2+SHA-256.

A scalable, secure and lightweight IoT device connector service for IoT is presented in this paper. The proposed framework addresses the issue of scalability of device onboarding and as well as providing a cryptographically strong security on top of a lightweight IoT protocol. In our proposed system, the devices are connected to the server over lightweight Message Queue Telemetry Transport (MQTT) protocol and Elliptic Curve Cryptography (ECC) is used for public key authenticated encryption of the payload. The client applications of IoT service consume the device data using HTTP REST API with JSON for seamless integration with other external IT systems over the internet, thus making the system scalable both in terms of device onboarding and as well as external service interfacing. State of the art ECC based NACL library is used as public key cryptosystem for both ECDH key agreement and ECDSA digital signature. Experimental results shows no significant variation in round-trip time compared between plain text and NACL encrypted payload. Also the performance test of the IoT device connector service shows that the Little’s law is upheld.

Maintaining a balance between anonymity and traceability is a fundamental issue in privacy-preserving systems. Isshiki et al. proposed an identity management system based on group signatures in which a service provider anonymously determines whether or not users of the service are legitimate members, and only a bill collector can identify users for the purposes of sending them invoices. It is particularly worth noting that, under the Isshiki system, the service provider is not required to manage personal information such as user lists, which allows the system to outperform other in terms of preserving user privacy and managing personal information leakage risk. It is also noteworthy that the Isshiki system only considers cases in which the bill collector identifies users who have used the service and that, in fact, identified users who ignore invoices can use the service for free. In this paper, we extended the Isshiki system by adding a smart contract-enabled enforcement bill collection functionality. Under this functionality, deposits made by users who do not pay a service fee are automatically transferred to the bill collector. Because of their centralized structure, group signatures are not suitable to blockchain systems, therefore, the proposed system employs accountable ring signatures as building blocks. The privacy-preserving enforced bill collection system is implemented using the accountable ring signature scheme developed by Bootle et al. and Ethereum smart contracts. To reduce the gas costs associated with running smart contracts, the smart contract is not run unless the user ignores an invoice, and basic procedures are run via an off-chain channel. To avoid the use of heavy cryptographic algorithms in carrying out the accountable ring signature scheme for running smart contracts, we employed standard elliptic curve digital signature algorithm (ECDSA) signatures without especially changing the state to be verified in smart contracts.

Device authentication is an important issue in Internet of Things (IoT) for enabling the connection of ubiquitous objects/things to the Internet. One of the emerging authentication approaches is based on some device characteristic (fingerprint) such as its type, firmware version, or signature. The usage of a Physically Unclonable Function (PUF) as device “digital fingerprint” for authentication has attracted great interest, however existing solutions present security drawbacks related to the authentication protocol, or to the poor reliability of the adopted PUF technology. The authentication protocol may require challenge-response pairs to be stored in a dependable repository, with an elevated risk of information leakage. To overcome the above limitations, this paper presents a reliable CMOS-PUF which produces a stable output that is used as private key in an authentication protocol based on Elliptic Curve Cryptography (ECC). The overall device architecture embeds the PUF and ECC components in a memory-less framework so that the device is resilient to cyberattacks and capable to perform authentication tasks with a stable and durable identity. The main advantages of the proposed framework are that no challenge–response pairs need to be previously stored, and no error correction mechanism is needed. A prototype implementation of the CMOS-PUF is sketched and three important key points (Randomness, Circuit Reliability and Security) of the proposed device authentication scheme are discussed as well.

Elliptic Curve Cryptography (ECC) is one of the common used standard methods for encrypting and signing messages which is essential when it comes to IoT communication. In this paper we discuss the side channel analysis attack resistance of our fast dual-field ECDSA accelerator. We present our implementation of a design supporting four different NIST Elliptic Curves to allow the reader to understand the discussion of the resistance aspects. Our key findings concerning the resistance are that the dual field design is by far more resistant against SCA than individual designs for B-curves. Here we were able to determine only two key candidates with a correctness above 85% for B-233 compared to the individual design of B-233 for which 6 key candidates with a correctness of more than 95% were revealed. In addition we were able to retrieve 4 candidates with a correctness of more than 97% for P-224 and even 3 fully correct key candidates for P-256. This is especially important as the design for ECs over GF(p) is realized using atomic patterns which is considered in the literature to ensure resistance against horizontal side-channel analysis attacks.

Satellite Based Augmentation System (SBAS) provides the corrections and integrity information to users, but as its signal format is opened to the public and Global Navigation Satellite System (GNSS) spoofing technology becomes more realistic, more feasible and cheaper. It's foreseeable that there will be risks of spoofing threats against SBAS in the future. SBAS signal authentication technology provides a system-level solution to spoofing threats by adding special markers to SBAS signals so that receivers can verify whether the SBAS signals are from the on-orbit Geostationary Earth Orbit (GEO) satellites or whether the signal information has been forged and tampered with. First, this article introduces the existing anti-spoofing methods that can be applied to SBAS, especially the Elliptic Curve Digital Signature Algorithm (ECDSA) and Timed Efficient Stream Loss-Tolerant Authentication (TESLA) protocols. Then it discusses four possible solutions in a combination with the existing SBAS Interface Control Document (ICD). Two main Key Performance Indicators (KPIs), Time Between Authentication (TBA) and Authentication Latency (AL), obtained in the four main scenarios are compared. By analyzing the EGNOS Authentication Security Testbed (EAST) test simulation results of European Geostationary Navigation Overlay Service (EGNOS) in Europe, the impact of SBAS after joining the authentication service is obtained.

With the development of new generation information technology, the feasibility of smart city has been significantly improved, and a large number of smart city technologies have been proposed. In this context, a more feasible device access technology is of great significance to ensure the normal operation of smart city network services. Therefore, this paper proposes a secure blockchain device access scheme based on elliptic curve digital signature algorithm and zero knowledge proof algorithm.

Cryptography is the science or process used for the encryption and decryption of data that helps the users to store important information or share it across networks where it can be read only by the intended user. In this paper, Elliptic Curve Cryptography (ECC) has been proposed because of its small key size, less memory space and high speed. Elliptic curve scalar multiplication is an important part of elliptic curve systems. Here, the scalar multiplication is performed with the help of hybrid Karatsuba multiplier as the area utilization of Karatsuba multiplier is less. An alternative of digital signature algorithm, that is, Elliptic Curve Digital Signature Algorithm (ECDSA) along with the primary operations of elliptic curves have also been discussed in this paper.

In recent times, security and privacy concerns associated with IoT devices have caught the attention of research community. The problem of securing IoT devices is immensely aggravating due to advancement in technology. These IoT devices are resource-constraint i.e. in terms of power, memory, computation, etc., so they are less capable to secure themselves. So we need a better approach to secure IoT devices within the limited resources. Several studies state that for these lightweight IoT devices Elliptic Curve Cryptography (ECC) suits perfectly. But there are several elliptic curve domain parameter standards, which may be used for different security levels. When any ECC based product is deployed then the selection of a suitable elliptic curve standard according to usability is become very important. So we have to choose one suitable standard domain parameter for the required security level. In this paper, two different elliptic curve standard domain parameters named secp256k1 and secp192k1 proposed by an industry consortium named Standards for Efficient Cryptography Group (SECG) [1] are implemented and then analyzed their performances metrics. The performance of each domain parameter is measured in computation time.

Cloud computing has reached the peak of Gartner hype cycle, and now the focus of the whole telecom industry is the ability to scale data storage with minimal investment. But data privacy and communication issues will occur with the increment of the cloud data storage. The key privacy concern for scalability is caused by the dynamic membership allocation and multi-owner data sharing. This paper addresses the issues faced by multiple owners through a mutual authentication mechanism using the Enhanced Elliptic Curve Diffie - Hellman (EECDH) key exchange protocol along with the Elliptic Curve Digital Signature Algorithm (ECDSA). The proposed EECDH scheme is used to exchange the secured shared key among multiple owners and also to eliminate the Man-In-The-Middle (MITM) attacks with less computational complexity. By leveraging these algorithms, the integrity of data sharing among multiple owners is ensured. The EECDH improves the level of security only slightly increasing the time taken to encrypt and decrypt the data, and it is secured against the MITM attacks, which is experimented using the AVISPA tool. Keywords: Cloud computing, Multi-owner, Diffie-hellman key exchange protocol, Elliptic curve digital signature algorithm, Station to station protocol, Enhanced elliptic curve diffie hellman

The Ukrainian National Standard for Digital Signature DSTU 4145-2002 has been in use about 17 years. During this time, significant changes have occurred in the field of information technology, which directly affect the implementation of the current National Standard for Digital Signature DSTU 4145-2002 and indicate the need for its modernization.Due to the need to revise and update national digital signature standard DSTU 4145-2002, the authors considered several digital signature constructions. Among the requirements to modern public-key signatures it is worth to highlight at least 128-bit security, fast signing and fast signature verification, fast keys generation, foolproof session keys, collision resistance, secure software implementation, etc. There are a lot of obvious variants in classic and elliptic signature systems, ElGamal, Schnorr`s, ECDSA, etc, which can be used in transitional to post quantum period.This paper introduces one of possible modifications for signature schemes based on the Edwards-curve Digital Signature Algorithm (EdDSA). The main advantages of the modification proposed in this work are:1) the signature scheme is secure even if the session key generator fails;2) signature implementation time does not depend on message length;3) security against related-key attacks., Украинский Национальный Стандарт Цифровой Подписи ДСТУ 4145-2002 используется уже почти 17 лет. За это время в области информационных технологий произошли существенные изменения, которые непосредственно влияют на применение этого стандарта и указывают на необходимость его модернизации.В связи с необходимостью пересмотра и обновления Национального стандарта цифровой подписи ДСТУ 4145-2002 авторы рассматривают несколько конструкций цифровых подписей. Среди требований к современной цифровой подписи следует упомянуть как минимум 128-битовый уровень стойкости, быстрые алгоритмы подписи и её проверки, быструю генерацию ключей, надёжность сеансовых ключей, стойкость к коллизиям, безопасная программная реализация и тд. Существует множество очевидных вариантов среди классических и эллиптических систем подписи, Эль-Гамаля, Шнорра, ECDSA, другие, которые могут использоваться в переходный период к постквантовой криптографии.Предлагается одна из возможных модификаций схемы цифровой подписи, базирующейся на алгоритме The Edwards-curve Digital Signature Algorithm (EdDSA). Основные преимущества предложенной в этой работе модификации состоят в следующем:1) схема подписи является стойкой даже в случае сбоя генератора сеансовых ключей;2) время реализации подписи не зависит от длины сообщения;3) стойкость к атаке со связанными ключами., Український Національний Стандарт Цифрового Підпису ДСТУ 4145-2002 використовується вже майже 17 років. За цей час у галузі інформаційних технологій відбулись суттєві зміни, які безпосередньо впливають на використання цього стандарту та вказують на необхідність його модернізації.У зв’язку з необхідністю перегляду та оновлення Національного стандарту цифрового підпису ДСТУ 4145-2002 автори розглядають кілька конструкцій цифрових підписів. Серед вимог до сучасного цифрового підпису слід зазначити як мінімум 128-бітовий рівень стійкості, швидкі алгоритми підпису та його перевірки, швидку генерацію ключів, надійність сеансових ключів, стійкість до колізій, безпечну програмну реалізацію і т. і. Існує багато очевидних варіантів серед класичних та еліптичних систем цифрового підпису, Ель-Гамаля, Шнорра, ECDSA, інші, які можна використовувати у перехідний до постквантового періода.Пропонується одна з можливих модифікацій схеми цифрового підпису, що базується на алгоритмі The Edwards-curve Digital Signature Algorithm (EdDSA). Основними перевагами модифікації, яка запропонована у цій роботі, є наступні:1) схема підпису є стійкою навіть у випадку збоїв у роботі генератора сеансовіх ключів;2) час реалізації підпису не залежить від довжини повідомлення;3) стійкість до атаки зі зв’язаними ключами.

This paper proposes a BeiDou-II navigation message authentication scheme to defend against the generating spoofing attacks. In this scheme, a digital signature is generated by the elliptic curve digital signature algorithm and is inserted into the reserved bits of the BeiDou-II navigation message. This signature will verify the integrity and authenticity of the navigation data to avoid entity masquerade and data tampering. Furthermore, the key exchange process is also designed through the short message service or digital certificate. The effectiveness and security of the scheme is evaluated in the simulation. The results indicate that the authentication of BeiDou-II navigation message can be realized in the harsh environment, and the resistance ability of civil BeiDou-II against a spoofing attack could be enhanced by this scheme.