Efficient Certificateless Aggregate Signature Scheme Research Articles

DRCLAS: An efficient certificateless aggregate signature scheme with dynamic revocation in vehicular ad-hoc networks

The emergence of the Vehicular Ad-hoc Networks (VANETs) has greatly enhanced the efficiency and safety of transportation systems. However, due to the dynamicness and openness of vehicular networks, it is vulnerable for VANETs to confront various security threats. The dissemination of disinformation and the occurrence of attacks within these networks can result in severe damage and compromise the overall security of transportation systems. To mitigate such challenges, this paper presents an efficient certificateless aggregate signature scheme with dynamic revocation in VANETs. Taking use of the early-stopping factorial bitwise divisions (EFBD) algorithm, it achieves the invalid signatures tracking, and revokes the malicious vehicles dynamically. In addition, by combining the fingerprint counting bloom filter (FP-CBF), the trust assessment mechanism and the cloud server, it enables the vehicle to remedy its incorrect signatures. At last, through the comprehensive security and performance analysis, it demonstrates that this protocol enjoys improved communication security and computational efficiency.

Cryptanalysis of Two Privacy-Preserving Authentication Schemes for Smart Healthcare Applications

Ensuring the secure sharing of privacy-sensitive healthcare data is attracting considerable interest from researchers. Recently, Ogundoyin et al. designed a lightweight privacy-preserving authentication scheme named PAASH for smart health applications. Benil et al. proposed a public verification and auditing scheme named ECACS for securing e-health systems. Ogundoyin et al. and Benil et al. proposed an efficient certificateless aggregate signature (CLAS) scheme as their respective foundation signature schemes. They declared that their constructions were provably secure under the hardness assumption of cryptographic problems. In this work, we disprove their claim by analyzing the correctness and security of their underlying CLAS schemes. We first show that the batch verification process of n signatures for the CLAS scheme in PAASH is incorrect, and any public-key replacement attacker can easily break the scheme. We analyze the reasons for our attack and propose an improved scheme, named PAASH+. We then show that the CLAS scheme in ECACS fails to achieve correctness, an essential property that a cryptographic scheme should provide. As a result, it is impractical to deploy the designed PAASH and ECACS constructions in any real smart health applications.

A Novel Construction Of Certificateless Aggregate Signature Scheme For Healthcare Wireless Medical Sensor Networks

Abstract To ensure privacy and security of healthcare wireless medical sensor networks (HWMSNs), several concrete constructions of efficient certificateless aggregate signature (CLAS) scheme without bilinear pairing were proposed in the last few years. However, many previous constructions of CLAS scheme were found to be impractical, which either fail to meet the claimed security or contain design flaws. For example, in some of the previous proposals, any adversary can forge a valid signature on any new message. In this paper, we first demonstrate some security issues and design flaws in the previous proposals of CLAS scheme. As follows, to further address the above deficiencies, a new construction of CLAS scheme with improved security is presented, and the formal security proof is given using Forking Lemma in the random oracle model, assuming that the discrete logarithm problem is hard. Compared with the previous CLAS schemes, our construction has similar computational costs, and it provides better security guarantees. Therefore, compared with the existing solutions, our proposal with strong security and high computational efficiency is more suitable for use in HWMSNs.

Efficient Certificate-Less Aggregate Signature Scheme with Conditional Privacy-Preservation for Vehicular Ad Hoc Networks Enhanced Smart Grid System.

Vehicular Ad hoc networks (VANETs) as spontaneous wireless communication technology of vehicles has a wide range of applications like road safety, navigation and other electric car technologies, however its practicability is greatly hampered by cyber-attacks. Due to message broadcasting in an open environment during communication, VANETs are inherently vulnerable to security and privacy attacks. However to address the cyber-security issues with optimal computation overhead is a matter of current security research challenge. So this paper designs a secure and efficient certificate-less aggregate scheme (ECLAS) for VANETs applicable in a smart grid scenario. The proposed scheme is based on elliptic curve cryptography to provide conditional privacy-preservation by incorporating usage of time validated pseudo-identification for communicating vehicles besides sorting out the KGC (Key Generation Center) escrow problem. The proposed scheme is comparatively more efficient to relevant related research work because it precludes expensive computation operations likes bilinear pairings as shown by the performance evaluation. Similarly, communication cost is within the ideal range to most related works while considering the security requirements of VANETs system applicable in a smart grid environment.

A Revocable Certificateless Aggregate Signature Scheme with Enhanced Security

In certificateless public key cryptosystem, a tough problem is how to revoke a user when the user's private key is compromised or expired. So the revocable certificateless schemes come into being. Certificateless aggregate signature (CLAS) is an efficient way to verify a large amount of signatures from different users simultaneously. However, none of CLAS schemes considers the user revocation currently. In this paper, we firstly demonstrate that an efficient certificateless aggregate signature (abbreviated to ECLAS) scheme proposed by Kang et al. is vulnerable to forged signature attack from the type II adversary by a concrete example, although they claimed that their scheme is existentially unforgeable against the adaptively chosen-message attacks. Furthermore, based on the ECLAS scheme and the revocable idea, we proposed a revocable certificateless aggregate signature scheme, which was proved to be existentially unforgeable against adaptive chosen-messages attacks under the hardness assumption of computational Diffie-Hellman problem. As far as we know, this is the first revocable CLAS scheme. Finally, numerical analyses and performance comparisons show our scheme saves computational cost, communication bandwidth and storage space than some related schemes.

An Efficient Certificateless Aggregate Signature Scheme for Blockchain-Based Medical Cyber Physical Systems.

Different from the traditional healthcare field, Medical Cyber Physical Systems (MCPS) rely more on wireless wearable devices and medical applications to provide better medical services. The secure storage and sharing of medical data are facing great challenges. Blockchain technology with decentralization, security, credibility and tamper-proof is an effective way to solve this problem. However, capacity limitation is one of the main reasons affecting the improvement of blockchain performance. Certificateless aggregation signature schemes can greatly tackle the difficulty of blockchain expansion. In this paper, we describe a two-layer system model in which medical records are stored off-blockchain and shared on-blockchain. Furthermore, a multi-trapdoor hash function is proposed. Based on the proposed multi-trapdoor hash function, we present a certificateless aggregate signature scheme for blockchain-based MCPS. The purpose is to realize the authentication of related medical staffs, medical equipment, and medical apps, ensure the integrity of medical records, and support the secure storage and sharing of medical information. The proposed scheme is highly computationally efficient because it does not use bilinear maps and exponential operations. Many certificateless aggregate signature schemes without bilinear maps in Internet of things (IoT) have been proposed in recent years, but they are not applied to the medical field, and they do not consider the security requirements of medical data. The proposed scheme in this paper has high computing and storage efficiency, while meeting the security requirements in MCPS.

Efficient Certificateless Aggregate Signature With Conditional Privacy Preservation in IoV

As an extension of traditional vehicular ad hoc networks, the Internet of Vehicles (IoV) enables information collection and dissemination, which brings a lot of convenience and benefits to the intelligent transportation systems. However, the booming IoV confronts a few challenges in the aspects of vehicle location privacy preservation and the authenticity of the transmitted information. In order to meet these challenges, we propose an efficient certificateless aggregate signature scheme with conditional privacy preservation in this article. Our scheme utilizes the technique of full aggregation to reduce the bandwidth resources and computing overhead. Besides, the conditional privacy preservation in IoV system is realized by using pseudonym mechanism. We demonstrate that the proposed scheme is secure against the Type-I and Type-II adversaries in the random oracle under the computational Diffie–Hellman assumption. In addition, the proposed scheme is compared with related works from aspects of computation cost, communication efficiency, and security requirements. The comparison results show that the proposed scheme is efficient, and it is suitable for resource-constrained environments.

Secure and efficient certificateless aggregate signature scheme from bilinear pairings

ABSTRACTThe most important contribution of modern cryptography is the invention of digital signatures. To deal with specific application scenarios, digital signature schemes have been evolved with different variants. One of such variants is the aggregate signature scheme, which allows aggregation of different signatures by different users on different messages, to achieve computational and communication efficiency. Such schemes are useful in the design of Wireless Sensor Networks, Mobile Ad-hoc Networks, and Vehicular Ad-hoc Networks, where storage, bandwidth, and computational complexity are major constraints. In order to improve the computational and communicational efficiency along with security, in this paper, we propose a novel Certificateless Aggregate Signature (CLAS) scheme and extended it to achieve full aggregation. The proposed CLAS scheme uses bilinear pairings over elliptic curves and is proven secure in the Random Oracle Model under the assumption that Computational Diffie–Hellman Problem is hard. The security of the proposed CLAS scheme is proven without using forking lemma to achieve tight security. We compared our scheme with well-known existing schemes. Efficiency analysis shows that our scheme is much efficient than existing schemes in terms of communication and computational costs.

An Efficient and Secure Certificateless Aggregate Signature From Bilinear Maps

Certificateless signature schemes are a very intriguing aspect in information security because of its capability of removing the well-known key escrow problem predominately in ID-based cryptography. He et al. proposed an efficient certificateless aggregate signature scheme and proved that their scheme is secure against all possible types of security attacks. However, the authors still managed to find loopholes in the form of insecurities against ‘honest but curious' and ‘malicious but passive' attacks during cryptanalysis of He et al.'s scheme. The authors propose an efficient certificateless aggregate signature scheme which fills the security gaps in He et al.'s scheme and demonstrate the security in their scheme via a mathematical proof, and reinforce the fact that their scheme is much more efficient in a thorough performance comparison of their scheme against the previous schemes.

An efficient certificateless aggregate signature scheme for the Internet of Vehicles

AbstractIn recent years, the research of Internet of vehicles (IoV) has received extensive attention. In IoV, vehicles can make intelligent decisions by exchanging the real‐time traffic information between other vehicles and IoV infrastructures, thereby reducing the probability of traffic jams and accidents. Although IoV has many advantages, it is necessary to ensure that the data are not edited, forged, or disclosed during the transmission. Also, the certificateless signature (CLS) seems to be the solution to this problem. While in the high‐intensity data transmission environment, the CLS scheme is inefficient for application. To improve the efficiency, the function of aggregation was introduced into the CLS. The certificateless aggregate signature (CL‐AS) can aggregate multiple signatures into a brief signature, reducing the computational cost and the size of signature. Nevertheless, most of the recent proposed CL‐AS schemes have problems of security or efficiency. In this paper, we presented an advanced efficient CL‐AS scheme with elliptic curve cryptography for the IoV environment. In addition, the proposed scheme uses pseudonyms in communications to prevent vehicles from revealing their identity. We proved the security of our proposal in the random oracle based on computational Diffie‐Hellman assumption. Also, the efficiency analysis and simulation show the superiority of our scheme.

Probably Secure and Efficient Certificateless Aggregate Signature Scheme

Probably Secure and Efficient Certificateless Aggregate Signature Scheme

An improved certificateless aggregate signature scheme without bilinear pairings for vehicular ad hoc networks

Certificateless aggregate signature (CL-AS) is a digital signature technique used to achieve improved performance in resource-constrained environments like vehicular ad hoc networks (VANETs) by eliminating the certificate issue in the traditional public key cryptography (PKC), addressing the key escrow problem in identity-based PKC, and utilizing the efficiency benefits of aggregate signature. Recently, an efficient CL-AS scheme for VANETs was proposed which the authors claimed to be existentially secure against forgery attacks in the random oracle model. In this paper, the scheme was analyzed and found to be insecure under existing security model. Consequently, we propose a new efficient certificateless aggregate signature scheme for VANETs applications based on elliptic curve cryptography. The proposed scheme does not only meet the privacy and security requirements for VANETs, but supports batch verification, autonomy, and conditional privacy preservation. In addition, the proposed scheme is provably secure against existential forgery on adaptive chosen message attack in the random oracle model based on the hardness assumption of the elliptic curve discrete logarithm problem. Extensive efficiency analysis demonstrates that the performance of the proposed scheme exceeds those of the recent related schemes in terms of computation cost and communication overhead.

An efficient certificateless aggregate signature scheme

Aggregate signature can aggregate n signatures on n messages from n signers into a single signature that convinces any verifier that n signers sign the n messages, respectively. In this paper, by combining certificateless public key cryptography and aggregate signatures, we propose an efficient certificateless aggregate signature scheme and prove its security. The new scheme is proved secure against the two representative types adversaries in certificateless aggregate signature under the assumption that computational Diffie-Hellman problem is hard. Furthermore, from the comparison of the computation cost of the new scheme with some existing certificateless aggregate signature schemes in group sum computation, scalar multiplication computation, Hash computation and abilinear pairings computation, it concludes that the new scheme reduces the computation cost in scalar multiplication computation in half and maintains the same in the other computation costs.

NCLAS: a novel and efficient certificateless aggregate signature scheme

Aggregate signature algorithms combine n signatures on n different messages from n distinct users into one aggregated signature. The aggregated signature allows the verifier to authenticate the n signatures simultaneously. Because the total signature length and authentication costs are significantly reduced, aggregate signature algorithms are attractive to applications with resource constraints and applications requiring efficient batch authentications. In this paper, we propose a novel aggregate signature scheme based on certificateless-PKC. Under this novel scheme, the length of the aggregated signature and the pairing computation cost in the aggregate signature verification process are independent of the number of signatures being aggregated. We also prove that the proposed scheme is existentially unforgeable against adaptive chosen-message and chosen-identity attacks, based on the hardness assumption of the computational Diffie-Hellman problem. The new scheme will be suitable for resource-constrained applications. Copyright © 2016 John Wiley & Sons, Ltd.

An efficient certificateless aggregate signature scheme for vehicular ad-hoc networks

Distributed Computing and Networking The state-of-the-art telecommunication technologies have widely been adapted for sensing the traffic related information and collection of it. Vehicular Ad-Hoc Networks (VANETs) have emerged as a novel technology for revolutionizing the driving experiences of human. The most effective and widely recognized way for mutual authentication among entities in VANETs is digital signature scheme. The new and attractive paradigm which eliminates the use of certificates in public key cryptography and solves the key escrow problem in identity based cryptography is certificateless cryptography. A new certificateless aggregate signature scheme is proposed in the paper for VANETs with constant pairing computations. Assuming the hardness of computational Diffie-Hellman Problem, the scheme is proved to be existentially unforgeable in the random oracle model against adaptive chosen-message attacks.

Comment on New Construction of Efficient Certificateless Aggregate Signatures

Aggregate signature can combine n signatures on n messages from n users into single signature, and the verifier should be convinced by the aggregate signature that n users indeed sign n messages. Since aggregate signature can greatly reduce the length of total signature and the cost of verification, it is widely used in environments with low bandwidth communication, low storage and low computability. Recently, Liu et al. [H Liu, S Wang, M Liang and Y Chen, “New Construction of Efficient Certificateless Aggregate Signatures”, International Journal of Security and Its Applications Vol.8, No.1 (2014), pp. 411-422] proposed an efficient certificateless aggregate signature scheme which is proven existentially unforgeable against adaptive chosen-message attacks. Unfortunately, Liu et al.’s new certificateless signature scheme is insecure. In this paper, giving concrete and simple attacks, we demonstrate that type II adversary key generation center can make ordinary-passive attack and malicious-active attack to forge legal certificateless signatures and certificateless aggregate signatures on any messages. Furthermore, we analyze possible reasons why key generation center succeeds in ordinary-passive attack and malicious-active attack.

Cryptanalysis and improvement of a certificateless aggregate signature scheme

Aggregate signature can combine n signatures on n messages from n users into a single short signature, and the resulting signature can convince the verifier that the n users indeed signed the n corresponding messages. This feature makes aggregate signature very useful especially in environments with low band width communication, low storage and low computability since it greatly reduces the total signature length and verification cost. Recently, Xiong et al. presented an efficient certificateless aggregate signature scheme. They claimed that their scheme was provably secure in a strengthened security model, where the “malicious-but-passive” KGC attack was considered. In this paper, we show that Xiong et al.’s certificateless aggregate signature scheme is insecure even against “honest-but-curious” KGC attack, an improved scheme which is really secure against “malicious-but-passive” KGC attack in the random oracle model. Performance analysis shows that our new scheme is more efficient than the other secure certificateless aggregate signature schemes.

Notes on the security of certificateless aggregate signature schemes

Secure aggregate signature schemes are very useful tools in special areas where the signatures on many different messages generated by many different users need to be compressed. Quite recently, an efficient certificateless aggregate signature scheme was presented by Xiong et al. (2013). Although they proved its security in the random oracle model under the standard computational Diffie–Hellman assumption, we find that their conclusion is wrong. In this paper, we give security analysis to their scheme by showing four kinds of concrete attacks. The first two kinds of attacks come from an honest-but-curious KGC and a malicious-but-passive KGC respectively. While the last two are from the collusion of inside signers or the collusion of an insider signer with a malicious-but-passive KGC. Our analysis indicates coalition attacks, especially those from the collusion of an inside signer with a malicious KGC are practical and destructive, and hence should be prevented in the design of CLAS schemes. We also put forward a secure certificateless aggregate signature scheme. Our new aggregate signature scheme results in a short aggregate signature that is valid if and only if every individual signature involved in the aggregation is valid.

New Construction of Efficient Certificateless Aggregate Signatures

This paper proposes a novel construction of efficient certificateless aggregate signature (CLAS) scheme. On basis of the computational Diffie-Hellman (CDH) assumption, the proposed scheme can be proven existentially unforgeable against adaptive chosen-message attacks. The new scheme also requires small constant pairing computations for aggregate verification, which is independent of the number of signers. Most importantly, a certain synchronization for aggregating randomness can be avoided by the proposed scheme. All the signers don’t need to share the same synchronized clock to generate the aggregate signature, which greatly decreases the implementation complexity in many application scenarios.

An efficient certificateless aggregate signature with constant pairing computations

An aggregate signature scheme enables an algorithm to aggregate n signatures of n distinct messages from n users into a single short signature. This primitive is useful in resource-constrained environment since they allow bandwidth and computational savings. Recently, in order to eliminate the use of certificates in certified public key cryptography and the key-escrow problem in identity-based cryptography, the notion of certificateless public key cryptography was introduced. In this paper, we present an efficient certificateless aggregate signature scheme with constant pairing computations. The security of the proposed scheme can be proved to be equivalent to the standard computational Diffie–Hellman problem in the random oracle with a tight reduction. Furthermore, our scheme does not require synchronization for aggregating randomness, which makes it more suitable for ad hoc networks.