Aggregate Signature Scheme Research Articles

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.

A Lightweight Certificateless Aggregation Signature Scheme With Provably Security in the Standard Model

In an aggregate signature scheme, $n$ signatures on $n$ different messages from $n$ users can be combined into a single signature. By verifying the signature, the verifier believes that $n$ users did generate the $n$ corresponding signatures. In the recent decade, numerous certificateless aggregate signature (CLAS) schemes have been introduced. There are two issues with these schemes. First, it was in the random oracles model (ROM) that the security proofs of these schemes were given. ROM is an idealized model. A signature scheme is not necessarily secure in real life even if it has proven to be safe in ROM. Second, the number of hash-to-point operations increases linearly with the number of signers in these schemes, so that are not suited for the computation-constrained devices (such as mobile devices). In this article, a new certificateless signature scheme is constructed. Based on it, a new CLAS scheme is proposed. Under the hypothesis that it is hard to solve a computation Diffie–Hellman problem, two schemes are proved to be secure in the standard model. The CLAS scheme needs only three pairing operations and does not need a hash-to-point operation, taken into account the computation cost, it is more efficient than previous CLAS schemes.

Forgery attacks on two provably secure certificateless signature schemes

Recently, Hashimoto and Ogata proposed a constant-size certificateless aggregate signature scheme based on bilinear pairings. Karati et al. constructed a new certificateless signature scheme without bilinear pairings. The schemes were proven secure against both Type I and Type II adversaries in the random oracle model under the hardness assumptions of the Elliptic Curve discrete logarithm problem and the Computational Diffie–Hellman problem. In this paper, we first show that Hashimoto and Ogata is insecure against a Super-Type I adversary who knows the user secret key associated to the replaced public key and suggest its improvement to prevent our attack. We also show that Karati et al.’s scheme is entirely broken: anyone can forge certificateless signatures on any messages for any identities from only publicly known information without using any secret information. Thus, the scheme is trivially insecure against the Type I adversary who can replace user public keys and the Type II adversary who knows the master secret key. The attack shows that their security proofs against the Type I and Type II adversaries are flawed since these forgery attacks are never reflected in the proofs. Thus, it should be proposed security models that cover various forgery attacks due to algebraic relations in the underlying groups.

On the security of privacy‐preserving authentication scheme with full aggregation in vehicular ad hoc network

AbstractCertificateless aggregate signature (CLAS) scheme is a very important cryptographic technique used in many internet of things (IoT) applications like healthcare wireless sensor networks, industrial IoT, smart agriculture, and smart transportation to achieve privacy and integrity of transmitted information, and improved efficiency. Recently, a privacy‐preserving authentication scheme based on CLAS scheme for secure communication in vehicular ad hoc network (VANET) which can achieve complete aggregation was proposed. The authors demonstrated that their scheme is semantically secure in the random oracle model based on the intractability of the computational Diffie‐Hellman (CDH) problem under the consideration of type I and II attacks. However, by giving two concrete attacks, we show that the scheme is insecure in the standard security model. Consequently, we propose a fix by modifying the sign, verify, and aggregate‐verify algorithms of the scheme. Afterwards, we demonstrate that with this modification, the improved scheme is semantically secure against forgery attacks in the random oracle model under the intractability of the CDH problem. An analysis of the performance of the proposed scheme and the related schemes shows the former is much more efficient and suitable for practical application.

HOMOMORPHIC AGGREGATE SIGNATURE SCHEME WITH OUTSOURCING ALGORITHM BASED PRIVACY PRESERVING IN VANETS

One of the important paradigms of recent technological development has known to be Vehicular Ad-hoc Networks (VANETs) due to its current intelligent transportation network. Moreover, leakage of communication information or sensitive data in VANETs can leads to vulnerable attacks that may affect many properties and lives. For this reason, VANET systems need to have high-level security aspects. In addition, devices with less computing resources expected for fast computation power. Several researchers have analysed various privacy preserving models for VANETs to protect from different attacks, which is not enough to prevent from new attackers. In this research, a Homomorphic Aggregate Signature (HAS) scheme proposed for achieving unforgeable message attacks without having random oracle and new outsourcing algorithm is designed efficiently for exponential operations to reduce the computational cost in which matrices conjugate operation based on homomorphic mapping is used for achieving the security of both base and exponent numbers. In addition, a protocol based on privacy preserving is constructed for VANETs by using the proposed HAS scheme and outsourcing computing, in which the authentication is processed by presenting a proxy re-signature scheme. In this proposed protocol, RSU will act as an agent when TA authorizes it and OBU’s signatures are converted to TA’s signature by using RSU. Real-identity of OBU is traced by TA using its secret key when an unknown/malicious message is detected then the proposed protocol will provide traceability, privacy, and anonymity. Furthermore, pairing and exponential operations are not needed by the proposed scheme as ` complexity of calculations is reduced significantly for VANET system.

Cryptanalysis of Two Signature Schemes for IoT-Based Mobile Payments and Healthcare Wireless Medical Sensor Networks

Certificateless cryptography does not require any certificate for the public key authentication and users' public keys are transmitted with ciphertext/signatures or by making them available in the IoT-based public directory in a proper way. Due to these features, certificateless cryptosystems are considered as fundamental cryptographic buildingblocks to provide authenticity, integrity and non-repudiation suitable for IoT applications. Yeh proposed a transaction scheme based on a certificateless signature scheme for IoT-based mobile payments implementing on Android Pay. He showed that the CLS scheme was unforgeable against Type I and Type II adversaries under the intractability of the mathematical problem. Despite the security proofs, we show that Yeh's scheme is still insecure against both Type I and Type II adversaries. Recently, Gayathri et al. constructed a compact certificateless aggregate signature scheme for Healthcare Wireless Medical Sensor Networks. Their aggregate signatures are constant-size independent of the number of signers. In this paper, we show that anyone can forge certificateless aggregate signatures of their scheme on any sets of messages and identities from only publicly known information, i.e. their scheme is entirely broken. We then discuss some improvements.

Security Vulnerabilities of Four Signature Schemes From NTRU Lattices and Pairings

Certificateless cryptography solves the certificate management problem in public-key cryptography and the key-escrow problem in identity-based cryptography. Xie et al. proposed a certificateless signature scheme using NTRU lattices. They proved that their scheme was existential unforgeable for Type I and Type II adversaries under the intractability of the Small Integer Solution (SIS) problem on NTRU lattices in the random oracle model. Subsequently, Hung et al. proposed a revocable certificateless signature scheme on NTRU lattices that gave a revocation method via public channels to revoke illegal or compromised users. They also proved that their scheme was existential unforgeable for Type I, Type II and Type III adversaries under the intractability of the SIS problem. Recently, Wang et al. proposed a certificateless aggregate signature scheme from bilinear pairings and Rezaeibagha et al. proposed a new lightweight certificateless scheme for Industrial Internet of Things from bilinear pairings. The security of their schemes was proven for Type I and Type II adversaries under the intractability of some mathematical problems. In this paper, we show that the two schemes on NTRU lattices are insecure against Type I or Type II adversaries. We also point out invalidity of Wang et al. ’s scheme and vulnerability of Rezaeibagha et al. ’s scheme against Type I attacks. We then suggest some improvements to prevent our attacks.

A unified framework of identity-based sequential aggregate signatures from 2-level HIBE schemes

Identity-based sequential aggregate signature (IBSAS for short) schemes, introduced by Boldyreva et al. [CCS 2007], allow a large quantity of signers to generate one signature sequentially, in which these messages as well as their order can be attested by employing their identities. In such a scheme, storage space and bandwidth overhead can be reduced. To our best knowledge, though many concrete IBSAS schemes have been constructed in literature, none of them is constructed under a standard computational hardness assumption and unforgeable under the standard model. The problem of how to construct such schemes is still open. Latterly, Gentry et al. [PKC 2018] proposed a unified construction of SAS (i.e., abbreviated form of sequential aggregate signature) schemes by employing trapdoor permutation and ideal ciphers. Motivated by the above problem and hints, here we study how to construct IBSAS schemes in a new unified perspective. By employing 2-level HIBE (i.e., abbreviated form of hierarchical identity-based encryption) schemes, we present unified construction of IBSAS schemes and give a rigorous proof of their unforgeability. The unified construction is then instantiated to get a concrete IBSAS scheme, which has existential unforgeability under the standard model using a standard computational hardness assumption (i.e., the CDH assumption). An extra fruit is that it can be used to construct an existentially unforgeable IBSAS scheme using the Learning with Errors problem, which is constructed under a lattice hardness assumption for the first time. In the end, we show a detailed performance comparison among our schemes and previous ones.

Certificateless aggregate signature scheme secure against fully chosen-key attacks

Certificateless aggregate signature (CLAS) schemes enjoy the benefits of both certificateless cryptography and aggregate signature features. Specifically, it not only simplifies the certificate management without introducing the key escrow problem but also transforms many signatures into one aggregate signature to save communication and computation cost.CLAS is a powerful cryptographic tool, yet its security should be thoroughly analyzed before being implemented. In this paper, we give a new insight into the security of CLAS schemes. We introduce a potential and realistic attack called fully chosen-key attacks that has not been considered in the traditional security models and define the security model against fully chosen-key attacks. In contrast to the traditional models, the adversary is allowed to hold all the signers’ private keys and its goal is not to forge an aggregate signature but to output invalid single signatures that can be aggregated into a valid aggregate signature. We find there is no CLAS scheme secure in traditional security models that is secure against fully chosen-key attacks and then demonstrate how to reinforce the security of an existing scheme to withstand such an attack.

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.

CB-CAS: Certificate-Based Efficient Signature Scheme With Compact Aggregation for Industrial Internet of Things Environment

The notion of aggregation of data in Industrial Internet of Things (IIoT) environment is a common practice. It shortens the data and associated signatures to reduce the bandwidth requirement. The compact aggregate signature (CAS) scheme creates a constant length aggregate signature (AS). Thus, the length of the CAS is independent of the number of messages or signatures to be aggregated. This article presents the first pairing-free CAS scheme in certificate-based settings. Due to the certificate-based approach, the proposed scheme is free from key escrow and key distribution problems inherited in identity-based cryptography (IDC) and certificate-less cryptography (CLC), respectively. Being compact and pairing free, it is the least bandwidth-consuming and the most efficient provably secure aggregation method. The length and computational cost analysis show that the scheme is the most appealing to use in the IIoT environment.

Efficient identity based aggregate signcryption scheme using bilinear pairings over elliptic curves

Signcryption is a cryptographic primitive that performs signature and encryption simultaneously at a cost significantly lower than the traditional signature-then-encryption methodology. An aggregate signature scheme is a digital signature scheme that combines n signatures on n different messages from n different users to a single signature. In this paper, we propose an aggregate signcryption scheme in the identity based setting using bilinear pairings over elliptic curves by combining aggregate signatures with signcryption schemes. We prove that our scheme is secure and satisfies the unforgeability and confidentiality in the random oracle model with the assumptions that the CBDHP and BDHP are hard. Also our scheme is public verifiable and requires constant number of pairings for aggregate verification. Comparing with previous schemes of this kind, our scheme is more efficient in computation and communication.

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.

Efficient and Secure Pairing-Free Certificateless Aggregate Signature Scheme for Healthcare Wireless Medical Sensor Networks

Recent advancements in wireless communication technologies have led to the development of practical applications, such as infrastructure monitoring, earthquake monitoring, environment monitoring, remote healthcare monitoring, etc. In these applications, we may integrate the wireless sensor networks (WSNs) with Internet of Things (IoT), where sensor nodes join the Internet dynamically and use it to collaborate and accomplish their tasks. In e-healthcare system, wireless medical sensor nodes continuously monitor and collect the physiological information and transmit the same to healthcare professionals through IoT terminals. To overcome the limitations in communication and computational capabilities in sensors and to attain privacy in healthcare wireless medical sensor networks (HWMSNs), few signature schemes were proposed in the literature. However, most of these schemes are insecure against various attacks. Hence to ensure privacy and security in medical data, in this paper, we proposed an efficient pairing-free aggregate signature scheme for HWMSNs in certificateless system. We exploit aggregation technique in certificateless system without using pairings to reduce computational complexity and transmission overhead in transferring the data. Our scheme achieves full aggregation to improve communicational efficiency and performance analysis shows that the proposed scheme is more efficient.

An Aggregate Signature Scheme Based on a Trapdoor Hash Function for the Internet of Things.

With the rapid development of the Internet of Things (IoT), it becomes challenging to ensure its security. Identity authentication and integrity verification can be achieved by secure hash functions and digital signature algorithms for IoT applications. In order to solve the issues of bandwidth limitation and computational efficiency of secure communication in IoT applications, an aggregate signature scheme based on multi- trapdoor hash function is proposed in this paper. Firstly, to prevent key exposition, based on the elliptic curve discrete logarithm problem (ECDLP), we constructed a double trapdoor hash function (DTH) and proved its reliability. Secondly, the multi-trapdoor hash function (MTH) based on DTH is presented. Finally, an MTH-based aggregate signature scheme (MTH-AS) with constant signature length is proposed. Based on the assumption of ECDLP, the proposed scheme is proven unforgeable against adaptive chosen message attacks with the Forking Lemma. Different from the most signature schemes with bilinear mapping, the proposed scheme has higher computational efficiency and shorter aggregate signature length. Moreover, it is independent of the number of signers. Security analysis and performance evaluation has revealed that the proposed scheme is an ideal solution for secure IoT applications with limited computing power, storage capacity, or limited bandwidth, such as wireless sensor networks, vehicular ad hoc networks, or healthcare sensor networks.

PFCBAS: Pairing Free and Provable Certificate-Based Aggregate Signature Scheme for the e-Healthcare Monitoring System

Recently, one of the most popular technologies of the modern era, the Internet of Things, allows the deployment and usage of various real-time test beds in various smart applications. One such application is the e-healthcare, in which patients’ healthcare related data are transmitted to the nearest base station and then to a local or remote server as per the requirements. The data related to patients’ health are sensitive and need special protection, therefore, the integrity and authentication of the sources of data generation are paramount concerns. However, several authentication or signature schemes that have been introduced in the past for this purpose are ID-based or having certificate-less settings. In these settings, a central authority, known as a trusted authority (TA), creates and distributes the secret key of every user. Thus, knowing the secrete key by the TA is called key escrow problem. But, these proposed schemes suffer from key distribution problems, which limit their applications in various applications. To mitigate these issues, this paper presents a certificate-based pairing free aggregate signature scheme (CBPFAS). The proposed scheme uses the merits of public key cryptography (PKC) and identity-based PKC (IDBPKC). The scheme is proven to be unforgeable, assuming the hardness of elliptic curve discrete log problem (ECDLP). The performance analysis shows that the proposed CBPFAS scheme executes in $0.78(n+1)$ ms in comparison to $9.63+1.17$ n ms in [1] , $9.63+0.78$ n ms in [2] , $9.63+3.39$ n ms in [3] , and $9.63+1.17$ n ms in [4] . From these results, it is concluded that the proposed pairing free certificate-based aggregate signature scheme performs better than its counterparts.

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.

Cryptanalysis of a Certificateless Aggregate Signature Scheme for Healthcare Wireless Sensor Network

Certificateless aggregate signatures aggregate n signatures from n different users into one signature. Therefore, a verifier can judge whether all signatures are valid by verifying once. With this advantage, certificateless aggregate signatures are widely used in the environment of limited computing resources. Recently, a novel certificateless aggregate signature scheme was proposed by Kumar et al. This scheme’s security was claimed to be secure against two types of attackers under the random oracle model. In this paper, we indicate that their scheme is unable to achieve this security goal. We show an attack algorithm that the second type of attacker could forge a valid signature under an identity without the private key of the target user. Moreover, we demonstrate that the second type of attacker could forge a valid aggregate signature.

Data Storage Mechanism Based on Blockchain with Privacy Protection in Wireless Body Area Network.

Wireless body area networks (WBANs) are expected to play a vital role in the field of patient-health monitoring shortly. They provide a convenient way to collect patient data, but they also bring serious problems which are mainly reflected in the safe storage of the collected data. The privacy and security of data storage in WBAN devices cannot meet the needs of WBAN users. Therefore, this paper adopts blockchain technology to store data, which improves the security of the collected data. Moreover, a storage model based on blockchain in WBAN is proposed in our solution. However, blockchain storage brings new problems, for example, that the storage space of blockchain is small, and the stored content is open to unauthorized attackers. To solve the problems above, this paper proposed a sequential aggregate signature scheme with a designated verifier (DVSSA) to ensure that the user’s data can only be viewed by the designated person and to protect the privacy of the users of WBAN. In addition, the new signature scheme can also compress the size of the blockchain storage space.

Provably secure certificateless aggregate signature scheme with designated verifier in an improved security model

An aggregate signature (AS) scheme combines multiple signatures which is generated by many different users into a single one. This feature is very beneficial for diminishing storage cost, bandwidth and verification cost. Many previous attempts have been made for designing AS schemes, while the former security models have not clearly addressed coalition attacks, and most of the existing AS schemes cannot resist these kinds of attacks. In this study, the authors provide a modified security model of certificateless AS (CLAS) schemes and then give a new CLAS scheme. The security of their present scheme can be rigorously proved based on the computational Diffie-Hellman assumption in the random oracle model. Furthermore, their scheme can resist such coalition attacks, i.e. an AS in their scheme is valid iff all single signatures used to generate the AS are valid.