Certificateless Signature Research Articles

A New Certificateless Signature Scheme Provably Secure in the Standard Model

Certificateless cryptography eliminates the need of certificates from public-key cryptography and solves the key escrow problem in identity-based cryptography. Since Al-Riyami and Paterson introduced the concept of certificateless cryptography, there have been several proposals for certificateless encryption schemes and signature schemes provably secure in the random oracle model. In the random oracle paradigm, the schemes make use of cryptographic hash functions that are modeled as random oracles in the security proof. However, it has been shown that when random oracles are instantiated with concrete hash functions, the schemes may not be secure. Afterward, several certificateless signature (CLS) schemes provably secure without random oracles have been proposed. However, it turned out that all the schemes are insecure against type I or II adversaries. In this paper, we propose a new CLS scheme secure in the standard model under the computational Diffie–Hellman assumption. We then investigate the practical feasibility of our scheme.

A Lightweight Cryptographic Protocol with Certificateless Signature for the Internet of Things

The universality of smart-devices has brought rapid development and the significant advancement of ubiquitous applications for the Internet of Things (IoT). Designing new types of IoT-compatible cryptographic protocols has become a more popular way to secure IoT-based applications. Significant attention has been dedicated to the challenge of implementing a lightweight and secure cryptographic protocol for IoT devices. In this study, we propose a lightweight cryptographic protocol integrating certificateless signature and bilinear pairing crypto-primitives. In the proposed protocol, we elegantly refine the processes to account for computation-limited IoT devices during security operations. Rigorous security analyses are conducted to guarantee the robustness of the proposed cryptographic protocol. In addition, we demonstrate a thorough performance evaluation, where an IoT-based test-bed, i.e., the Raspberry PI, is simulated as the underlying platform of the implementation of our proposed cryptographic protocol. The results show the practicability of the proposed protocol.

An Efficient Authentication Scheme Based on Semi-Trusted Authority in VANETs

With the development of intelligent transportation systems, vehicular ad hoc networks (VANETs) are widely used in safety driving, and so on. However, existing signature schemes, such as pseudonym- and group-based schemes, have certain problems, such as the need for a certificate distribution and certificate revocation lists (CRLs). With such schemes, the vehicle needs to store a valid certificate generated by the management center. Simultaneously, the receiver needs to check the CRLs prior to message authentication. CRLs require large amounts of storage space and computational and communication resources. In addition, many such schemes are built on a trusted authority and do not meet real-world needs. Thus, we propose an efficient authentication scheme based on semitrusted authority in VANETs. In this scheme, we combine the self-healing key distribution method with a certificateless signature in a semitrusted authority environment, such that the receivers do not require to query the CRLs. Therefore, the vehicles do not have to store the CRLs, thereby saving storage space and communication resources. This also reduces the computational costs and improves the efficiency of the message authentication. Since the proposed scheme is built on a semitrusted authority, it is a more realistic approach.

Certificateless Sequential Aggregate Signature Scheme on NTRU Lattice

Having the advantages of certificateless signature and the aggregate signature at the same time, certificateless aggregate signature has been widely applied in e-business, e-government and software security since it was proposed in 2007. Although a number of certificateless aggregate signature schemes have been proposed, all of them are based on the classic number theory problem, which are no longer secure in the quantum era. In this paper, a certificateless sequential aggregate signature over number theory research unit lattice is proposed, which is proven to be secure in random oracle model. Moreover, we extend the new scheme into an efficient certificatebased sequential aggregate signature which is also secure in quantum era.

Efficient and Provably Secure Certificateless Parallel Key-Insulated Signature Without Pairing for IIoT Environments

With the continuous development of the industrial Internet of Things (IIoT), many organizations opt for storing the data collected by smart devices on a cloud server for saving costs. Considering the untrusted nature of the communication channel, how to ensure the authenticity of data is an urgent matter to be solved. Certificateless signatures that can provide an authentication mechanism for the data seem to be a viable option to this problem. Nevertheless, the certificateless signature scheme proposed so far is either easy to be broken or inefficient. In this paper, a pairing-free and provably secure certificateless parallel key-insulated signature (CL-PKIS) scheme is put forward for securing the communication in the IIoT environment. Unlike previous work in this field, our scheme not only uses elliptic curves to maintain higher efficiency, but also implants key-insulated primitive to reduce the risk of key exposures. Besides, our scheme provides a parallel mechanism to make it more suitable for the IIoT environment, which was not available in previous solutions. Finally, the security of our CL-PKIS scheme is proved under the discrete logarithm assumption in the random oracle model.

Top-Level Secure Certificateless Signature Against Malicious-But-Passive KGC

Certificateless signature (CLS) has no need of public key certificates and also avoids excessive dependence to a third party like that in identity-based setting. Recently, Shim (IEEE Systems Journal, doi:10.1109/JSYST.2018.2844809) came up with a CLS scheme independent of random oracles and asserted that the construction can be immune to the public key replacement attacks and the malicious-but-passive key generation center (KGC) attacks. In this paper, we analyze the security of Shim’s scheme and point out that his conclusions are incorrect by giving two concrete counter-examples. We repair the scheme and put forward a CLS scheme secure against public key replacement attacks and malicious-but-passive KGC attacks without relying on random oracles. Compared with Shim’s scheme, our construction has lower execution cost for signing and verification, and achieves Girault’s top-level security, which means that a victim can repudiate the forgeries based on a false secret key generated by the KGC.

Fully Secure Lightweight Certificateless Signature Scheme for IIoT

In recent years, Industrial Internet of Things (IIoT) has become increasingly important for applications in the industry. Inevitably, security for IIoT has become a priority in order to deploy secure applications. Amongst available cryptographic tools, certificateless signature schemes offer sound authentication solutions and avoid public-key certification from Trusted Third Parties (TTP). Certificateless signatures solve the key escrow problem against the dishonest Private Key Generator (PKG) and has considered to be a useful tool for IIoT applications. Recently, Karati et al. (IEEE Trans. Industrial Informatics, vol.14, no. 8, 2018) presented a lightweight certificateless signature scheme for IIoT Environments. This scheme was then broken by Zhang et al. (IEEE Access, vol. 8, 2018) by simply allowing to change the public key of the signer and using the homomorphic property of the original scheme. In this paper, we introduce a new attack to the scheme against the existential unforgeability, which is universal since we do not have to assume homomorphic property. We then introduce an entirely new lightweight certificateless signature scheme, which has been proven to be fully secure against all attacks found earlier. Our scheme is the first lightweight certificateless signature scheme with full security and is the most efficient in comparison with other existing schemes. It is desirable for IIoT applications. We also provide experimental results to justify our claims.

On the Security of an Efficient and Robust Certificateless Signature Scheme for IIoT Environments

As the progress of digitization in industrial society, large amount of production data are outsourced to the cloud server in order to reduce data management costs. Nevertheless, how to ensure the outsourced data integrality, validity, and availability is a challenging research topic. Recently, Zhang et al. (IEEE Trans. Industrial Informatic, doi:10.1109/TII.2019.2894108) presented an efficient and robust certificateless signature scheme to achieve the data authenticity for industrial Internet of Things (IIoT) environments. However, we found that their scheme is insecure. In this paper, we show that an attacker with replacing public key ability can easily impersonate other legitimate users to upload some false messages by forging the target users' valid signatures on these messages. Therefore, their certificateless signature scheme has not solved the IIoT data authenticity issue pointed out by them. Meanwhile, we also demonstrate that their security proof is not sound because the ability of an adversary cannot be applied to solve the difficult problem that they expect.

Security Analysis of a Certificateless Provable Data Possession Scheme in Cloud

He et al. proposed a certificateless provable data possession protocol for big data storage on cloud. They claimed that the scheme is not only secure, but also can achieve data integrity checking without downloading the stored data from the cloud server. However, in this paper, we show that He et al.'s protocol has some security flaw and cannot get the property of data integrity checking at all. Specifically, by observing certificateless signature used in their provable data possession protocol, we find that the cloud server (or any user who gets signature-message pairs) can generate a valid signature of any message. Then, the cloud server can tamper data stored by the data owner and successfully passes the data integrity checking via two different conditions according to the verifier knows or does not know the identity of blocks of data.

A New Provably Secure Certificateless Signature with Revocation in the Standard Model

A New Provably Secure Certificateless Signature with Revocation in the Standard Model

Pairing-free certificateless signature with revocation

Pairing-free certificateless signature with revocation

Remote Authentication Schemes for Wireless Body Area Networks Based on the Internet of Things

Internet of Things (IoT) is a new technology which offers enormous applications that make people’s lives more convenient and enhances cities’ development. In particular, smart healthcare applications in IoT have been receiving increasing attention for industrial and academic research. However, due to the sensitiveness of medical information, security and privacy issues in IoT healthcare systems are very important. Designing an efficient secure scheme with less computation time and energy consumption is a critical challenge in IoT healthcare systems. In this paper, a lightweight online/offline certificateless signature (L-OOCLS) is proposed, then a heterogeneous remote anonymous authentication protocol (HRAAP) is designed to enable remote wireless body area networks (WBANs) users to anonymously enjoy healthcare service based on the IoT applications. The proposed L-OOCLS scheme is proven secure in random oracle model and the proposed HRAAP can resist various types of attacks. Compared with the existing relevant schemes, the proposed HRAAP achieves less computation overhead as well as less power consumption on WBANs client. In addition, to nicely meet the application in the IoT, an application scenario is given.

A new VRSA‐based pairing‐free certificateless signature scheme for fog computing

SummaryFog computing is composed of various computers with weak performance instead of servers with strong performance. As history has shown, there has not been a general pairing‐free certificateless signature scheme that is mainly designed with modular exponentiation and modular multiplication that can possess resistance to Type I and Type II adversaries. The lightweight certificateless signature algorithm with low requirements for computing and storage capabilities, which can be practicably implemented in fog computing, needs to be studied. Therefore, a new hard mathematic problem is firstly defined in this paper, which is called variant of RSA problem. Then, a new general pairing‐free certificateless signature scheme is proposed based on the variant of RSA problem and the discrete logarithm problem. Fortunately, the proposed scheme is the first RSA‐based certificateless signature scheme that can possess resistance to Type I and Type II adversaries. A formal security proof is provided to demonstrate that, under adaptively chosen message attacks, the scheme is provably secure against Type I and Type II adversaries in the random oracle model. When compared with other known pairing‐free certificateless signature schemes of the same type, the computation cost of our scheme is slightly higher; however, a higher security level can be achieved.

A certificateless signature scheme with strong unforgeability in the random oracle model

A certificateless signature scheme with strong unforgeability in the random oracle model

Provably Secure and Lightweight Certificateless Signature Scheme for IIoT Environments

In recent years, two technologies, the cloud computing and the Internet of Things (IoT), have a synergistic effect in the modern organizations as digitization is a new business trend for various industries. Therefore, many organizations outsource their crowdsourced industrial-IoT (IIoT) data in the cloud system to reduce data management overhead. However, data authentication is one of the fundamental security/trust requirements in such IIoT network. The certificateless signature (CLS) scheme is a cryptographic primitive that provides data authenticity in IIoT systems. Recently, CLS has become a prime research focus due to its ability to solve the key-escrow problem in a very recent identity-based signature technique. Many CLS schemes have already been developed using map-to-point (MTP) hash function and random oracle model (ROM). However, due to the implementation difficulty and probabilistic nature of MTP function and ROM, those CLSs are impractical. Hence, the development of a CLS for lightweight devices mounted in IIoT has become one of the most focused research trends. This paper presents a new pairing-based CLS scheme without MTP function and ROM. The new CLS scheme is secure against both the Type-I and Type-II adversaries under the hardness of extended bilinear strong Diffie–Hellman (BSDH) and BSDH assumptions, respectively. Performance evaluation and comparison proves that our scheme outperforms other CLS schemes.

Enabling verifiable multiple keywords search over encrypted cloud data

Searchable Encryption (SE) enables a user to search over encrypted data, such as data stored in a remote cloud server. Existing certificate-, identity-, and attribute-based SE schemes suffer from certificate management or key escrow limitations. Furthermore, the semi-honest-but-curious cloud may conduct partial search operations and return a fraction of the search results (i.e., incomplete results) in order to reduce costs. In this paper, we present a secure cryptographic primitive, Verifiable Multiple Keywords Search (VMKS) over ciphertexts, which leverages the Identity-Based Encryption (IBE) and certificateless signature techniques. The VMKS scheme allows the user to verify the correctness of search results and avoids both certificate management or key escrow limitations. We then demonstrate the security of proposed VMKS scheme (i.e., the scheme achieves both ciphertext indistinguishability and signature unforgeability). We also use a real-world dataset to evaluate its feasibility and efficiency.

Leakage-Resilient Certificateless Signature Under Continual Leakage Model

In the past, the security notions of cryptography were modeled under the assumption that private (or secret) keys are completely hidden to adversaries. Nowadays, these security notions could be insufficient due to a new kind of threat, called “side-channel attacks”, by which an adversary obtains partial information of private (or secret) keys via employing specific properties resulting from physical implementations of cryptographic schemes. In order to resist such side-channel attacks, numerous leakage-resilient cryptographic schemes have been proposed. However, there is little work on studying leakage-resilient certificateless cryptographic schemes. In this article, we propose the first leakage-resilient certificateless signature (LR-CLS) scheme under the continual leakage model. In the generic bilinear group model, we demonstrate that our scheme possesses existential unforgeability against adaptive chosen-message attacks for both Type I and Type II adversaries. Finally, performance analysis is made to demonstrate that the proposed LR-CLS scheme is suitable for resource-constrained devices.DOI: http://dx.doi.org/10.5755/j01.itc.47.2.17847

A Secure Transaction Scheme With Certificateless Cryptographic Primitives for IoT-Based Mobile Payments

How to simultaneously achieve security robustness and maintain the usage convenience of mobile payments within insecure public communication networks is a crucial topic for intelligent mobile device manufacturers, telecommunication companies, and mobile users. In this paper, we introduce a secure transaction scheme with certificateless cryptographic primitives for mobile payments. The proposed scheme takes advantage of the merits of Android Pay and a refined certificateless signature cryptosystem to simultaneously deliver transaction security and achieve payment efficiency in practice. With a formally defined adversary model and security analysis, the proposed scheme is proven to be both accurate and secure via random oracle model. It provides strong transaction robustness and communication security to mobile users during online payment transactions. On the other hand, the performance evaluation shows the practicability of our proposed transaction scheme, as the total computation cost is acceptable for a common Internet of Things (IoT)-based testbed.

PCPA: A Practical Certificateless Conditional Privacy Preserving Authentication Scheme for Vehicular Ad Hoc Networks.

Vehicle ad hoc networks (VANETs) is a promising network scenario for greatly improving traffic efficiency and safety, in which smart vehicles can communicate with other vehicles or roadside units. For the availability of VANETs, it is very important to deal with the security and privacy problems for VANETs. In this paper, based on certificateless cryptography and elliptic curve cryptography, we present a certificateless signature with message recovery (CLS-MR), which we believe are of independent interest. Then, a practical certificateless conditional privacy preserving authentication (PCPA) scheme is proposed by incorporating the proposed CLS-MR scheme. Furthermore, the security analysis shows that PCPA satisfies all security and privacy requirements. The evaluation results indicate that PCPA achieves low computation and communication costs because there is no need to use the bilinear pairing and map-to-point hash operations. Moreover, extensive simulations show that PCPA is feasible and achieves prominent performances in terms of message delay and message loss ratio, and thus is more suitable for the deployment and adoption of VANETs.

A pairing-free and provably secure certificateless signature scheme

Certificateless Signature (CLS) scheme is a notable cryptographic technique for solving the key escrow problem in identity-based cryptosystem (IBC). In the CLS, the private key is computed collectively by both the key generation center (KGC) and the signer which ensures that no vindictive KGC masquerades the actual signer. Recently, a number of CLS schemes have been proposed using bilinear pairing and show their immunity under standard security model. It is well known that one such pairing operation requires significantly more computational cost than the other cryptographic operations. In this paper, we propose a new CLS scheme using elliptic curve cryptography (ECC), which does not require bilinear pairing operation. Our CLS scheme is analyzed formally and found to be provably secure against both the Type-I and Type-II attacks based on the intractability of elliptic curve discrete logarithm problem (ECDLP) under the random oracle model. Performance evaluation demonstrates that the proposed CLS scheme outperforms than other competitive CLS schemes.