Certificateless Signature Scheme Research Articles

Blockchain-enhanced efficient and anonymous certificateless signature scheme and its application

Although the Internet of Things (IoT) brings efficiency and convenience to various aspects of people’s lives, security and privacy concerns persist as significant challenges. Certificateless Signatures eliminate digital certificate management and key escrow issues and can be well embedded in resource-constrained IoT devices for secure access control. Recently, Ma et al. designed an efficient and pair-free certificateless signature (CLS) scheme for IoT deployment. Unfortunately, We demonstrate that the scheme proposed by Ma et al. is susceptible to signature forgery attacks by Type-II adversaries. That is, a malicious-and-passive key generation center (KGC) can forge a legitimate signature for any message by modifying the system parameters without the user’s secret value. Therefore, their identity authentication scheme designed based on vehicular ad-hoc networks also cannot guarantee the claimed security. To address the security vulnerabilities, we designed a blockchain-enhanced and anonymous CLS scheme and proved its security under the Elliptic curve discrete logarithm (ECDL) hardness assumption. Compared to similar schemes, our enhanced scheme offers notable advantages in computational efficiency and communication overhead, as well as stronger security. In addition, a mutual authentication scheme that satisfies the cross-domain scenario is proposed to facilitate efficient mutual authentication and negotiated session key generation between smart devices and edge servers in different edge networks. Performance evaluation shows that our protocol achieves an effective trade-off between security and compute performance, with better applicability in IoT scenarios.

An anonymous and efficient certificateless signature scheme based on blockchain in NDN‐IoT environments

An anonymous and efficient certificateless signature scheme based on blockchain in <scp>NDN‐IoT</scp> environments

Cryptanalysis and Improvement of a Blockchain-Based Certificateless Signature for IIoT Devices

With the rapid development of the Industrial Internet of Things (IIoT), security and privacy issues have become increasingly prominent when the data from IIoT devices is shared across public networks. Very recently, Wang <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">et</i> <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">al.</i> presented a blockchain-based certificateless signature (CLS) scheme for IIoT devices in order to achieve secure and lightweight communication (IEEE Transactions on Industrial Informatics, DOI: 10.1109/TII.2021.3084753). Wang et al. claimed that their CLS scheme is secure under the assumption of the elliptic curve discrete logarithm problem. Unfortunately, by providing two attack methods to analyze the security of Wang et al.'s CLS scheme, we find that it is insecure against universal forgery attacks. Without knowing any information about the target user's private key, the two categories of attackers can successfully forge the valid signature of any message. Hence, Wang et al.'s CLS scheme fails to achieve the claimed security goals. To fix the security flaws, we propose an enhanced blockchain-based and pairing-free CLS scheme, and prove its security in the random oracle model. Furthermore, the analysis results demonstrate that our revised scheme has higher security while keeping the performance of the original scheme.

Certificateless Signature Scheme with Batch Verification for Secure and Privacy-Preserving V2V Communications in VANETs

Certificateless Signature Scheme with Batch Verification for Secure and Privacy-Preserving V2V Communications in VANETs

Mobile Sensoring Data Verification via a Pairing-Free Certificateless Signature Secure Approach against Novel Public Key Replacement Attacks

To achieve flexible sensing coverage with low deployment costs, mobile users need to contribute their equipment as sensors. Data integrity is one of the most fundamental security requirements and can be verified by digital signature techniques. In the mobile crowdsensing (MCS) environment, most sensors, such as smartphones, are resource-limited. Therefore, many traditional cryptographic algorithms that require complex computations cannot be efficiently implemented on these sensors. In this paper, we study the security of certificateless signatures, in particular, some constructions without pairing. We notice that there is no secure pairing-free certificateless signature scheme against the super adversary. We also find a potential attack that has not been fully addressed in previous studies. To handle these two issues, we propose a concrete secure construction that can withstand this attack. Our scheme does not rely on pairing operations and can be applied in scenarios where the devices’ resources are limited.

An Efficient Certificateless Signature Scheme With Provably Security and Its Applications

The Internet of Things (IoT) is helpful in making people's life more convenient and efficient. To ensure that the nodes within IoT can interact securely, a certificateless signature (CLS) can be used to protect message authentication in the IoT. Recently, some concrete constructions of CLS schemes have been proposed in the literature, but through our analyses, we demonstrate that some existing CLS schemes cannot keep their claimed security because of various security flaws. For example, a valid signature can be forged by any Type I adversary by replacing the corresponding user's public key. In this article, we describe the security flaws that need to be addressed and introduce a novel CLS scheme without using bilinear mapping. The existential unforgeability in our proposed scheme can be proved based on the hardness of the elliptic curve discrete logarithm problem in the random oracle model. The comparison with existing CLS schemes shows that our scheme not only enjoys more security features but also is more efficient in computation. Moreover, we introduce an identity authentication protocol as the application of our proposed CLS scheme, which achieves mutual authentication and anonymity in communications.

Improving Throughput of Mobile Sensors via Certificateless Signature Supporting Batch Verification

Mobile sensors enjoy the advantages of easy installation and low consumption, which have been widely adopted in many information systems. In those systems where data are generated rapidly, the throughput of the sensors is one of the most fundamental factors that determine the system functionality. For example, to guarantee data integrity, digital signature techniques can be applied. In many practical scenarios, such as the smart grid system, data are generated rapidly and, hence, the signature together with the data must also be transmitted and verified in time. This requires the mobile sensors to support a high-throughput data processing ability. In this setting, how to achieve efficient signature schemes supporting batch verification must be considered. Many signatures, such as the original national cryptographic standard, namely, the SM2 algorithm, do not support batch verification and are in a public-key infrastructure setting. In this paper, we propose a SM2-based certificateless signature scheme with batch verification, which is suitable for the aforementioned environment. The scheme extends the Chinese cryptographic standard SM2 algorithm to the certificateless setting and multiple signatures can be verified simultaneously. Another advantage of this scheme is that its signing phase does not involve any pairing operation. The verification phase only requires a constant pairing operation, which is not related to the number of signatures to be verified. The construction is generic and can be instantiated using any traditional signature scheme.

A redesigned secure and efficient data transaction protocol for mobile payment system

Generally, the secure protocol was proposed from the certificateless signature (CLS) scheme to provide the corresponding security for the actual application. However, for the previous application protocols, most of the underlying CLS schemes cannot have their claimed security, because some proposals cannot resist forgery attacks or the master secret key can be captured by the probabilistic polynomial time adversary. To further address the above problems, we take several previous CLS schemes as instances to make a detailed analysis of the causes of the above security flaws and point out that, in a secure CLS scheme, we should appropriately publish the public parameters. Based on the above analysis, we design an efficient and secure CLS scheme in this paper, and the unforgeability is proved based on the hardness of discrete logarithm complexity assumption through the Forking lemma. Compared with the existing constructions, our new proposal has advantages in communication and computation efficiency but also has higher security. Furthermore, a concrete construction of a certificateless aggregate signature (CLAS) scheme is designed with the above basic CLS scheme to realize efficient verification of multiple signatures. Finally, we further improve the key conditions that need to be paid attention to design a secure CLS scheme.

An efficient privacy-preserving authentication scheme with enhanced security for IoMT applications

The Internet of Medical Things (IoMT), an essential application of Internet of Things (IoT) technology in the health sector, is of great practical importance in improving healthcare quality and reducing healthcare costs and errors. For years, researchers have designed many cryptographic schemes for securing IoMT applications. However, in this work, we reveal that the state-of-the-art cloud-centric IoMT-based smart healthcare system cannot be deployed in real-world scenarios by proposing a concrete signature forgery attack on their underlying pairing-based homomorphic certificateless signature (CLS) scheme. Then we present a new CLS scheme without pairings and formally prove its security under the standard cryptographic assumption. Based on our design, we put forward a new secure and efficient IoMT-based smart healthcare system. The performance comparison results illustrate the practicality of our construction.

An Efficient Pairing-Free Certificateless Signature Scheme with KGC Trust Level 3 for Wireless Sensor Network

With the widespread adoption of wireless sensor networks (WSN), the security of the WSN has been a wide concern. Certificateless signature eliminates the certificate management problem and key escrow problem and is considered a feasible solution to solve the data integrity and authentication of WSN. Recently, Thumbur et al. proposed an efficient pairing-free certificateless signature scheme, and Xu et al. pointed out that their scheme is not resistant to signature forgery attacks and proposed an improved scheme. Based on the trust hierarchy defined by Girault, we find that Xu et al.’s scheme is still only able to achieve security under KGC trust level 2. Moreover, Thumbur et al.’s scheme uses the Schnorr signature algorithm form, which makes it favorable for scaling, while Xu et al.’s scheme breaks this advantage. Therefore, we propose a pairing-free certificateless scheme capable of reaching KGC trust level 3, still using the Schnorr signature algorithm form, and prove the security of the new scheme under the random oracle model. The final efficiency analysis shows that the new scheme has shorter public key length and higher computational efficiency.

Cryptanalysis of a Transaction Scheme With Certificateless Cryptographic Primitives for IoT-Based Mobile Payments

Very recently, Qiao <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">et al.</i> (2021) constructed an efficient certificateless signature (CLS) scheme, and further used it as the underlying scheme to design a transaction scheme for IoT-based mobile payments. Their CLS scheme is claimed to be secure against Type I and II attackers. Unfortunately, in this article, we provide an attack method to demonstrate that their CLS scheme is insecure against Type II attackers. Furthermore, we present an improved CLS scheme to enhance the security of their scheme.

Blockchain-enhanced certificateless signature scheme in the standard model.

The Internet of Things (IoT), driven by wireless communication and other technologies, is gradually entering our lives and promoting the transformation of society from "informatization" to "intelligence". Certificateless signature (CLS) eliminates the characteristic of certificate management, making it an effective method for verifying large-scale data in the IoT environment. Nevertheless, hash functions are regarded as ideal random oracles in the security proofs of most CLS schemes, which cannot guarantee the security of CLS schemes in reality. In response to this problem, Shim devised a CLS scheme without random oracles in the standard model and declared it to be provably secure. Unfortunately, in this paper, we cryptanalyze Shim's CLS scheme and demonstrate that it is not resistant to public key replacement attacks from a Type Ⅰ attacker. Furthermore, to further improve the security of the Shim CLS scheme and avoid the single-point failure of the KGC and the signature forgery initiated, we propose a blockchain-based CLS scheme without a random oracle. Finally, we evaluate the comprehensive performance, and while maintaining the computational and communication performance of the Shim scheme, we resist both Type Ⅰ and Type Ⅱ attackers, as well as signature forgery initiated against public parameters.

ELCPAS: A new efficient lightweight certificateless conditional privacy preserving authentication scheme for IoV

This paper proposes a new efficient certificateless conditional privacy preserving authentication (CL-CPPA) scheme named ELCPAS, which is pairing-free, energy-efficient, lightweight which uses elliptic curve cryptography (ECC) for internet of vehicles (IoV). The ELCPAS is based on the certificateless signature scheme that eliminates the key escrow problem, which is the drawback of identity-based encryption. It performs batch message verification with a very efficient method which minimizes the delays in the message verification phase. In our proposed scheme, users (vehicle etc.) do not need to communicate with central units during each message signing. Thus, the computational load and connection problems in the central units are minimized. It is also quite fast as it does not use the bilinear pairing and map-to-point operations. The performance evaluation shows that ELCPAS has efficiency in scope of computation cost, communication cost and energy consumption cost compared to other existing schemes. The security evaluation is performed according to the random oracle model (ROM) and the proposed ELCPAS scheme has been shown to be secure. In addition, it provides security requirements and it is resistant to cyber-attacks. The results of the analyses performed according to the security criteria show that it is secure.

PSCLS: provably secure certificateless signature scheme for IoT device on cloud

PSCLS: provably secure certificateless signature scheme for IoT device on cloud

Prevention of Blackhole Attack in MANET using Certificate less Signature Scheme

Mobile AdHoc Networks (MANETs) are the network of self-configuring nodes. Such nodes communicate through single as well as multi-hop modes without the aid of any centralized administrator or pre-existing network infrastructure. Due to this reason, MANETs have gained a highly significance in modern wireless networking technologies. Such networks are extremely vulnerable to one of the security attack i.e. blackhole attack. It is a malicious node when an attacker is able to send a fake route reply to the originator of a route request packet. Such attackers discard the legitimate packets and replay packets in the whole network thereby adversely affecting network performance. Most of the security protocols for MANET are using bilinear pairing methods to provide security against security attacks and it takes high computing cost for the computation of pairing operations. Nowadays, researchers are using certificate-less signature schemes in distributed environments to provide efficient security. This signature scheme is very popular because it does not use any certificate authority for the management of security certificates. In this paper, we proposed an efficient technique to prevent blackhole attack in MANET using RSA-based certificateless signature scheme without using any bilinear pairing operations. Our scheme provides security against forgery and blackhole attacks and is evaluated under a discrete logarithm problem. Proposed scheme outperforms existing schemes in terms of these metrics viz., throughput, packet delivery ratio, routing overhead and end-to-end delay when we are varying mobility and fixed percentage of malicious nodes. Our proposed scheme not only detects or prevents the blackhole attack but it is also capable to provide important security services viz., integrity, authentication and non-repudiation.

Blockchain-Based Reliable and Efficient Certificateless Signature for IIoT Devices

Nowadays, the Industrial Internet of Things (IIoT) has remarkably transformed our personal lifestyles and society operations into a novel digital mode, which brings tremendous associations with all walks of life, such as intelligent logistics, smart grid, and smart city. Moreover, with the rapid increase of IIoT devices, a large amount of data is swapped between heterogeneous sensors and devices every moment. This trend increases the risk of eavesdropping and hijacking attacks in communication channels, so maintaining data privacy and security becomes two notable concerns at present. Recently, based on the mechanism of the Schnorr signature, a more secure and lightweight certificateless signature (CLS) protocol is popular for the resource-constrained IIoT protocol design. Nevertheless, we found most of the existing CLS schemes are susceptible to several common security weaknesses such as man-in-the-middle attacks, key generation center compromised attacks, and distributed denial of service attacks. To tackle the challenges mentioned previously, in this article, we propose a novel pairing-free certificateless scheme that utilizes the state-of-the-art blockchain technique and smart contract to construct a novel reliable and efficient CLS scheme. Then, we simulate the Type-I and Type-II adversaries to verify the trustworthiness of our scheme. Security analysis as well as performance evaluation outcomes prove that our design can hold more reliable security assurance with less computation cost (i.e., reduced by around 40.0% at most) and communication cost (i.e., reduced by around 94.7% at most) than other related schemes.

A Multivariate-Based Provably Secure Certificateless Signature Scheme With Applications To The Internet Of Medical Things

Abstract Over the last few years, Internet of Medical Things (IoMT) has completely transformed the healthcare industry. It is bringing out the most notable, and unprecedented impacts on human health, and has totally changed the way we look at the healthcare industry. The healthcare sector all around the globe are leapfrogging, and adopting the technology, helping in transforming drastically in a very short span of time. However, as more and more number of medical devices are being connected to IoMT, security issues like ensuring authenticity and integrity of the transmitted data are also on the rise. In view of the context, there is a need of an efficient cryptographic primitive that can address these issues in a viable manner. A signature scheme seems to be the natural choice to mitigate the security concerns. But, traditional signature schemes, both public-key-infrastructure-based and Identity-based, have their own disadvantages, which makes them unsuitable for IoMT networks. Thus, to address the security issues and problems like certificate management and key escrow, herein, we put forward the first multivariate-based certificateless signature scheme, namely, Multivariate Certificateless Signature (Mul-CLS), which is built on top of the intractability of multivariate-quadratic (MQ) problem. The fact that multivariate public key cryptosystem provides fast, post-quantum safe and efficient primitives makes it a front-runner candidate among the other post-quantum cryptography candidates. Our scheme Mul-CLS provides existential unforgeability against chosen message and chosen identity Super Type I and Super Type II adversary if solving the MQ problem is NP-hard. In addition to that, our proposed Mul-CLS presents itself as a robust and cost-friendly cryptographic building block for building IoMT networks.

Secure medical data management with privacy-preservation and authentication properties in smart healthcare system

The potential of combining Internet-of-Medical-Things technology with medical cloud storage can greatly improve the current smart healthcare environment. But some critical obstacles arise when developing the two technologies. One of the most difficult aspects is how to efficiently guarantee medical data’s privacy and authentication since the biomedical sensors (BMSs), implanted on patient’s body, have very limited battery life and computing abilities. Another one is to check the integrity of data stored on medical cloud. In this paper, we propose a secure and lightweight, especially for the BMSs, data management model for healthcare system, in which a BMS only needs to perform symmetric encryption consisting of XOR and message-authentication-code (MAC) operations. The adopted encryption technique ensures the privacy and authentication of medical data. Moreover, an aggregated homomorphic certificateless signature scheme is also proposed for the personal-assisted device and server device, which guarantees the public verifiability of medical data stored on cloud. Meanwhile, the certificateless property naturally implies that the whole system is immune to key-escrow attack. Finally, the detailed performance analysis and comparisons with related works show that our proposed system is very competitive in terms of communication overheads and computational costs.

Public Integrity Auditing of Shared Encrypted Data within Cloud Storage Group

The pandemic of COVID-19 has posed a severe challenge to the traditional on-site centralized development projects; people therefore have to share data in a group by the cloud storage server and develop projects at home. The cloud server is untrustworthy, although it supplies the powerful computing capability and abundant storage space; so far wide research has been proposed to verify data integrity. Therefore, how to leverage the cloud server and ensure the integrity of the data (especially the encrypted data) stored on the remote cloud devices remains an issue for the clients. To address this issue, we utilize the technique of homomorphic hash function to implement reencryption ciphertext blocks and introduce a certificateless signature scheme for the integrity verification of encrypted data shared within a group. A detailed challenge-and-response game represents that the proposed scheme can preserve encrypted data blocks integrity against the internal/external attacker and malicious cloud service servers. We give the theoretical and experimental performance analysis of the scheme and exhibit that the scheme is efficient and practical.

Design Principles of Secure Certificateless Signature and Aggregate Signature Schemes for IoT Environments

Certificateless cryptography resolves the certificate management problem of public-key cryptography and the key-escrow problem of identity-based cryptography. An aggregate signature scheme which allows to aggregate <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i> distinct signatures on <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i> distinct messages of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i> distinct signers into a single signature reduces communication overhead and computational cost. Due to the suitability of certificateless signature (CLS) and certificateless aggregate signature (CLAS) schemes for IoT environments, similar CLS and CLAS schemes have been proposed for a long time and, despite their security proofs, they have been attacked and modified to prevent the attacks. Even now, similar design methods and similar attacks on the schemes are being repeated. In order to prevent the similar attacks on the schemes, it is necessary to analyze their causes and vulnerabilities. In this paper, we first show that recently proposed five CLS and CLAS schemes are insecure against universal forgery attacks, type I attacks, type II attacks or malicious-but-passive-KGC attacks. We discuss their security flaws, causes and countermeasures. We then present design principles to prevent various algebraic attacks including our attacks. The design principles will help in the construction of secure CLS and CLAS schemes against the previous attacks and potential attacks.