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Wireless medical sensor networks (WMSNs) are playing an increasingly important role in smart healthcare applications. Since the data transmitted in WMSNs is closely related to patient's life and health, and considering the resource-constrain feature of the sensor node, constructing an authentication scheme for WMSNs is a formidable task. Recently, Soni et al. presented an elliptic curve cryptosystem based three-factor authentication scheme for WMSNs. However, we discover that their scheme suffers from serious vulnerabilities, such as sensor node capture attack, no forward secrecy, and the violation of three-factor security. To enhance the security and efficiency, we present a novel scheme using Rabin cryptosystem and chaotic maps. We use several widely-accepted security analysis methods to verify the correctness and security of our scheme. The Burrows-Abadi-Needham logic proof confirms the completeness of our scheme. The heuristic analysis indicates that our scheme is resistant to potential attacks and provides various security attributes like forward secrecy and three-factor security. Furthermore, we demonstrate that our scheme is provably secure in the random oracle model. Finally, the performance comparisons indicate that our scheme is superior to the related schemes both in security and efficiency and is more applicable to WMSNs owing to low overhead of the sensor node.

Fully homomorphic encryption (FHE) is a form of public-key encryption that allows the computation of arbitrary functions on encrypted data without decrypting the data. As a result, it is a useful tool with numerous applications. Certificateless encryption (CLE) is a type of public-key encryption that combines the advantages of PKI-based public-key encryption with those of identity-based encryption (IBE). Thus, certificateless fully homomorphic encryption (CLFHE) has aroused considerable research interest. Recently, Chen, Hu, and Lian proposed a leveled certificateless homomorphic encryption (CLHE) scheme and proved its semantic security based on the learning with errors (LWE) problem in the random oracle model. However, their scheme supports only homomorphic addition, but not homomorphic multiplication. In this work, we construct two leveled CLFHE schemes using the approximate eigenvector method presented by Gentry, Sahai, and Waters. Based on the hardness of the LWE problem, we prove that one scheme satisfies adaptive semantic security and anonymity in the random oracle model, whereas the other satisfies selective semantic security and anonymity in the standard model.

Related-key attack (RKA) is a kind of side-channel attack considered for kinds of cryptographic primitives, such as public key encryption, digital signature, pseudorandom functions etc. However, we note that the RKA-security seems to be not considered for identity-based signature (IBS), which is an important primitive for identity-based cryptography and proposed by Shamir in 1984. In this paper, for the first time, we introduce the RKA security into IBS schemes and try to define the security model for it. More specifically, we consider the RKA occurs in the users' signing key or the master key of the key-generation center (KGC), which derives two kinds of RKA securities for IBS. Meanwhile, we illustrate that the most efficient Schnorr-like IBS scheme proposed by Galindo and Garcia is RKA-insecure by launching a simple RKA. However, a slight modification of it yields a RKA-secure IBS scheme, for which we give the detailed security proof in the random oracle. Finally, the performance analysis shows that the modified scheme is still extremely efficient but has higher security.

Vehicle Ad hoc Networks (VANETs) are an emergent wireless communication technology that has the potential to reduce the risk of accidents caused by drivers and provide a wide range of entertainment facilities. Because of the nature of VANETs' open-access environment, security attacks can affect the messages broadcast by a vehicle. VANET is therefore vulnerable to security and privacy issues. Recently, many schemes for addressing these problems of VANET have been proposed. However, most of them are affected by massive computation overhead and security issues. In this paper, we propose a scheme named efficient conditional privacy preservation with mutual authentication to address the problems mentioned above in VANET. This scheme depends on the division of geographical areas into a number domains and their distribution, where each domain stores the Certificate Revocation List (CRL) in all Road-side Units (RSUs) located inside the domain. During the mutual authentication phase, the vehicle should authenticate with the TA. After the vehicle obtains a pool of pseudo-identities and the corresponding secret keys from RSU, it is allowed to transmit a message to the other components in the VANET. Because our scheme does not use the bilinear pairing, the performance evaluation shows that our scheme has a lower system cost in terms of computation and communication than other existing methods. Meanwhile, the proposed scheme reduces the computation costs of signing the message and verifying the message by 99.85% and 99.93%, respectively. While the proposed scheme reduces the communication costs of the message size by 13.3%.

Over the past years, vehicular ad hoc networks (VANETs) have been commonly used in intelligent traffic systems. VANET's design encompasses critical features that include autonomy, distributed networking, and rapidly changing topology. The characteristics of VANET and its implementations for road safety have attracted considerable industry and academia interest, particularly in research involving transport systems enhancement that could potentially save lives. Message broadcasting in an open access system, such as VANET, is the main and utmost challenging problem with regard to security and privacy in VANETs. Various studies on VANET security and privacy have been proposed. Nevertheless, none has considered overall privacy requirements such as unobservability. In order to address these shortcomings, we propose a VANET based privacy-preserving communication scheme (VPPCS), which meets the requirements for content and contextual privacy. It leverages elliptic curve cryptography (ECC) and an identity-based encryption scheme. We have carried out a detailed security analysis (burrows-abadi-needham (BAN) logic, random oracle model, security of proof, and security attributes) to validate and verify the proposed scheme. The analysis has shown that our scheme is secure and also shown to be effective in a performance evaluation. The proposed scheme does not only meet the previously mentioned security and privacy requirements, but also impervious to various types of attacks such as replay, impersonation, modification, and man-in-the-middle attacks.

Recently, Vehicle Ad Hoc Networks (VANETs) have been increasingly developed in Intelligent Transportation Systems (ITSs). However, VANETs are vulnerable to security issues because of the open-medium nature of Vehicle-To-Vehicle (V2V) and Vehicle-To-Infrastructure (V2I) communication. Recently, many studies have proposed security schemes to address these issues. However, many of these schemes have massive computational overheads, especially in the process of batch verification method, which verifies multiple messages simultaneously. In this article, a Lightweight Security Without Using Batch Verification Method (LSWBVM) scheme is proposed based on Elliptic Curve Cryptography (ECC). The proposed LSWBVM scheme uses the XOR operation and general hash function during mutual authentication. Meanwhile, to verify a large number of messages, the proposed scheme uses an efficient single verification instead of batch verification in a high traffic density-area. BAN logic proves that the LSWBVM achieves the security goals to mutually authenticate between the nodes. The security analysis indicates that the LSWBVM satisfies the security requirements, such as: identity privacy preserving, tractability and revocability; and secure non-forgery under the random oracle model in an adaptively chosen message attack. The preference evaluation shows that the single verification of proposed LSWBVM is more efficient when compared with batch verification of the related works.

Internet of Energy (IoE) provides two-way communication for reform of energy utilization between service providers and consumers. To provide secure, efficient, and reliable operations in IoE should be protected from cyber-attacks. Many frameworks have been proposed so far to address security and privacy concerns of these systems. In the vehicle-grid system, we propose a useful mutual authenticated key agreement framework using elliptic curve cryptography and hash function. The aim of the proposed protocol is to maintain secure communication between vehicles and the grid system with reliable computation and communication costs. In the proposed protocol, a vehicular user securely access services that are provided by the grid server. We prove the security of the proposed framework in formal and informal ways. We also show the correctness of the mutual authentication and key agreement of this framework by using Burrows–Abadi–Needham logic. We provide formal security verification of the proposed protocol by using AVISPA tool. Further, we show that this work is better in terms of computation and communication costs compare to other related protocols in the same environment. As a result, the proposed framework is a real life-application in this system. [ABSTRACT FROM AUTHOR]

Attribute-based encryption (ABE) is an advanced cryptographic tool and useful to build various types of access control systems. Toward the goal of making ABE more practical, we propose key-policy (KP) and ciphertext-policy (CP) ABE schemes, which first support unbounded sizes of attribute sets and policies with negation and multi-use of attributes, allow fast decryption, and are adaptively secure under a standard assumption, simultaneously. Our schemes are more expressive than previous schemes and efficient enough. To achieve the adaptive security along with the other properties, we refine the technique introduced by Kowalczyk and Wee (Eurocrypt'19) so that we can apply the technique more expressive ABE schemes. Furthermore, we also present a new proof technique that allows us to remove redundant elements used in their ABE schemes. We implement our schemes in 128-bit security level and present their benchmarks for an ordinary personal computer and smartphones. They show that all algorithms run in one second with the personal computer when they handle any policy or attribute set with one hundred attributes. [ABSTRACT FROM AUTHOR]

In a proxy re-signature scheme, a semi-trusted proxy can convert Alice's (also called as delegatee's) signature into Bob's (also called as delegator's) signature on the same message. However, the proxy itself cannot produce any signatures on behalf of either Alice or Bob. There exists some unidirectional one-use and multi-use (a message can be re-signed a polynomial number of times) proxy re-signature schemes. In some scenarios of big data, it is required to design unidirectional infinite-use (a message can be re-signed infinite number of times) proxy re-signature schemes. In this paper, we propose the first unidirectional infinite-use proxy re-signature scheme and identity-based unidirectional infinite-use proxy re-signature scheme with private re-signature keys based on lattice and prove that they are secure in the random oracle model. [ABSTRACT FROM AUTHOR]

Aiming at the anonymity of vehicle identity and message authentication security problems in Internet of Vehicles information interaction. At present, many schemes are constructed by bilinear pairings, which have low computational efficiency, high communication cost and key escrow problem. This paper proposed a certificateless aggregated signature scheme suitable for Internet of Vehicles. The vehicle 's key was jointly generated by the KGC and the vehicle, which avoided the problem of key escrow. This solution did not use a bilinear pairing operation, and supported aggregate verification. The signature length did not show an increasing trend with the increase in the number of vehicles. Under the random oracle model, based on the discrete logarithm problem on the elliptic curve, it proves that the scheme has signature unforgeability. Through performance analysis, the scheme has higher calculation efficiency and lower communication overhead. [ABSTRACT FROM AUTHOR]

The Internet provides us a lot of online services. Under the conventional single-server architectures, remote users must register separately on each visited server to obtain the required services. In contrast, with a multi-server architecture, users can freely access subscribed services from multiple servers by registering at a single registration center (R C). Currently, biometrics are widely applied in user authentication schemes to improve their security. Combining with biometric authentication techniques, we present an anonymous authentication scheme by using Chebyshev chaotic map to achieve authentication of both communicating parties in multi-server scenario. The core point of this new scheme is the use of chaotic mapping to achieve mutual authentication instead of time-consuming authentication methods, thus leading to higher efficiency. Based on the widely used Real-Or-Random(ROR) model and the Proverif tool, we perform a formal security analysis of the proposed scheme. In addition, the comparison of security attributes and performance with other related works indicates that the new scheme can withstand various attacks and better suited to multi-server application scenarios. [ABSTRACT FROM AUTHOR]

Compact multisignature is vital for shrinking the signature size of decentralized blockchain. All practical compact multisignature schemes have been constructed from the discrete logarithm problem which is potentially vulnerable to quantum computing attacks. Lattice-based multisignature schemes are potential candidates for resisting quantum attacks. However, the existing lattice-based multisignature schemes suffer either loose signatures or large public key and signature sizes after compressing, which makes them unsuitable for blockchains. In this paper, we first present a practical lattice-based multisignature scheme with much smaller signature sizes than previous lattice-based multisignature schemes. Then, we extend our scheme to support public key aggregation with almost the same performance. Both of our multisignature schemes are provably secure in the random oracle model under the ring version of the short integer solution (Ring-SIS) assumption. They outperform the recent lattice-based multisignature scheme proposed by Bansarkhani and Sturm (BS) in terms of both signature size and communication overhead.

A conventional divisible E-cash (DEC) system allows each user to withdraw a coin of value 2n, then spend it in several times by dividing it into small ones of value 2l, for some l ∈ {0, 1, ⋯, n}. Observing that the price of many commodities is not just 2l, it requires to pay more than one coin in a transaction. In order to improve the efficiency of spend protocol, we propose a new construction called arbitrarily DEC (ADEC) which can divide a large coin into several small ones with arbitrarily integer values. We propose a new construction of ADEC based on a public linked list. Using bilinear pairings, we instantiate two ADEC systems: one holds its useful properties in the standard model and the other one in the random oracle model. These two systems allow users to pay for transactions in constant time. Moreover, our construction can be applied to secure the E-commerce of merchant with high volumes of transactions, a merchant can get a result in constant time for depositing a coin and can complete the deposit procedure in a reasonable time, even if he/she deposits massive coins. Our schemes are quite practical for users/merchants using resource-constrained mobile devices.

A ring signature is an anonymous signature that implements both the authentication of the message and the anonymity of the signer. In a “normal” ring signature scheme, the same signer can generate multiple ring signatures, but the verifier cannot find this fact. Linkable ring signature (LRS) solves the problem. In the setting, the identity of the signer is still anonymous, and if the same signer generates multiple ring signatures, the verifier can confirm the fact. Linkable ring signatures are applied to some actual scenarios, such as e-cash, e-voting and ad-hoc network authentication. In this paper, we presented a new identity-based linkable ring signature scheme that avoids certificate management. We then gave the security proofs in the random oracle model (ROM) and compared the efficiency of it with the previous schemes. The new scheme requires only 7 pairing operations in signing and verifying. It is the most efficient linkable ring signature in the identity-based setting.

Deniable authenticated encryption (DAE) is a cryptographic primitive that supports data confidentiality with deniable authentication in an efficient manner. The DAE plays a significant role in location-based service systems for privacy protection. In this paper, we construct a certificateless DAE (CLDAE) scheme. The CLDAE is based on certificateless cryptosystems (CLCs), which avoids the need to manage public key certificates in public key infrastructure (PKI)-based cryptosystems and key escrow problems in identity-based cryptosystems (IBCs). Our design utilizes hybrid methods: tag-key encapsulation mechanism (TKEM) and data encapsulation mechanism (DEM). This technique is more suitable for location-based applications. We show how to construct a CLDAE scheme utilizing a certificateless deniable authenticated tag-KEM (CLDATK) and a DEM. We also design a CLDATK scheme and provide formal security proof using the random oracle model (ROM). We conduct a comprehensive performance analysis, which shows that CLDAE is highly efficient in terms of communication overhead. We also provide an application of the CLDAE for a location-based service (LBS) system.

Summary: Designing an efficient, short, and secure authentication algorithm for resource‐constrained sensor nodes of wireless sensor networks (WSNs) is a challenging task. Authentication in WSNs is mainly performed by the digital signature algorithm. In this paper, we propose an efficient, short, and secure pairing computation‐free ID‐based authentication algorithm (signature scheme) ESS‐IBAA for WSNs which completely follows the rule of identity‐based cryptosystem. Identity‐based schemes, unlike traditional public‐key infrastructure (PKI)‐based schemes, remove the need for public‐key certificates for public‐key validation. It also removes extra costs associated with the public‐key certificate and traffic management. Further, due to the requirement of low power and fast authentication, bilinear pairing computation‐free identity‐based signature schemes are applicable in WSNs. Keeping this in mind, ESS‐IBAA scheme is proposed, which is pairing computation free and uses a general cryptographic hash function in the place of a costly map‐to‐point hash function. The proposed scheme ESS‐IBAA is secure against existential forgery on adaptive chosen message and ID attack in the random oracle model under the hardness of the elliptic curve discrete logarithm problem (ECDLP). Moreover, comparative performance analysis shows that the proposed scheme ESS‐IBAA is much more efficient in both communication cost and computation cost from the existing related schemes. [ABSTRACT FROM AUTHOR]

Non-interactive zero-knowledge (NIZK) proofs for chosen-ciphertext security are generally considered to give an impractical construction. An interesting recent work by Seo, Abdalla, Lee, and Park (Information Sciences, July 2019) proposed an efficient semi-generic conversion method for achieving chosen-ciphertext security based on NIZK proofs in the random oracle model. The recent work by Seo et al. demonstrated that the semi-generic conversion method transforms a one-way (OW)-secure key encapsulation mechanism (KEM) into a chosen-ciphertext secure KEM while preserving tight security reduction. This paper shows that the security analysis of the semi-generic conversion method has a flaw, which comes from the OW security condition of the underlying KEM. Without changing the conversion method, this paper presents a revised security proof under the changed conditions that (1) the underlying KEM must be chosen-plaintext secure in terms of indistinguishability and (2) an NIZK proof derived from the underlying KEM via the Fiat–Shamir transform must have the properties of zero-knowledge and simulation soundness. This work extended the security proof strategy to the case of identity-based KEM (IBKEM) and also revise the security proof for IBKEM of previous method by Seo et al. Finally, this work gives a corrected security proof by applying the new proofs to several existing (IB)KEMs. [ABSTRACT FROM AUTHOR]

Digital signatures are unsuitable for specific applications that are sensitive on a personal or commercial level because they are universally verifiable. Jakobsson et al. proposed the Designated Verifier Signature (DVS) system, which only allows the intended verifier to validate a message’s signature. It prohibits the disclosure of a conviction to a third party. This functionality is useful in applications that require both authenticity and signer privacy, such as electronic voting and tender calls. The vast majority of current DVS schemes are based on difficult number theory problems such as integer factorization or discrete log problems over various groups. The development of a large-scale quantum computer would render these schemes unsafe. As a result, it is critical to develop quantum-resistant DVS methods. In both quantum and classical computers, signatures based on one-way functions are more efficient and secure. They have several advantages over digital signatures based on trapdoor functions. As a result, hash-based signatures are now considered viable alternatives to number-theoretic signatures. Existing hash-based signatures, on the other hand, are easily verifiable by anyone. As a result, they do not protect the signer’s identity. In addition, they are one-time signatures. This paper presents a hash-based multi-time designated verifier signature scheme that ensures signer anonymity. The unforgeability of the signature scheme is also tested in the random oracle model under chosen message attack. The properties such as non-transferability and non-delegatability are investigated.

The Internet of Things (IoT) is a future trend that uses the Internet to connect a variety of physical things with the cyber world. IoT technology is rapidly evolving, and it will soon have a significant impact on our daily lives. While the growing number of linked IoT devices makes our daily lives easier, it also puts our personal data at risk. In IoT applications, Radio Frequency Identification (RFID) helps in the automatic identification of linked devices, and the dataflow of the system forms a symmetry in communication between the tags and the readers. However, the security and privacy of RFID-tag-connected devices are the key concerns. The communication link is thought to be wireless or insecure, making the RFID system open to several known threats. In order to address these security issues, we propose a robust authentication framework for IoT-based RFID infrastructure. We use formal security analysis in the random oracle model, as well as information analysis to support the claim of secure communication. Regarding the desirable performance characteristics, we describe and analyze the proposed framework’s performance and compare it to similar systems. According to our findings, the proposed framework satisfies all security requirements while also improving the communication.

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Existing identity-based schemes utilized in Vehicular Ad hoc Networks (VANETs) rely on roadside units to offer conditional privacy-preservation authentication and are vulnerable to insider attacks. Achieving rapid message signing and verification for authentication is challenging due to complex operations, such as bilinear pairs. This paper proposes a secure pseudonym-based conditional privacy-persevering authentication scheme for communication security in VANETs. The Elliptic Curve Cryptography (ECC) and secure hash cryptographic function were used in the proposed scheme for signing and verifying messages. After a vehicle receives a significant amount of pseudo-IDs and the corresponding signature key from the Trusted Authority (TA), it uses them to sign a message during the broadcasting process. Thus, the proposed scheme requires each vehicle to check all the broadcasting messages received. Besides, in the proposed scheme, the TA can revoke misbehaving vehicles from continuously broadcasting signed messages, thus preventing insider attacks. The security analysis proved that the proposed scheme fulfilled the security requirements, including identity privacy-preservation, message integrity and authenticity, unlinkability, and traceability. The proposed scheme also withstood common security attacks such as man-in-the-middle, impersonation, modification, and replay attacks. Besides, our scheme was resistant against an adaptive chosen-message attack under the random oracle model. Furthermore, our scheme did not employ bilinear pairing operations; therefore, the performance analysis and comparison showed a lower resulting overhead than other identity-based schemes. The computation costs of the message signing, individual signature authentication, and batch signature authentication were reduced by 49%, 33.3%, and 90.2%, respectively.

To expand the application field of designated confirmer signature, this paper introduced a concept of decentralized attribute-based designated confirmer signature (DABDCS) by combing the concepts of attribute-based and decentralization with designated confirmer signatures. It presented the formal definition and security model of DABDCS, and proposed a concrete scheme. The scheme was based on Cramer et al. 's witness hiding protocol, in which Schnorr identification was chosen as its basis L.: protocol, and Shamir threshold scheme as its secret sharing scheme. Based on the threshold signature scheme, it proposed a decentralized attribute-based designated confirmer signature scheme without bilinear pairings, and proved its securities under the random oracle model. The proposed scheme can be applied to multiple-party communication environments, such as electronic bidding and so on. [ABSTRACT FROM AUTHOR]

Universal Serial Bus (USB) is widely used, for example to facilitate hot-swapping and plug-and-play. However, USB ports can be exploited by an adversary to extract private or personal data from the connected devices. Hence, a number of organizations and workplaces have prohibited their employees from using USB devices, and there have been efforts to design secure USB storage device schemes to more effectively resist different known security attacks. However, designing such schemes is challenging. For example, in this article we revisit the Wei et al.’s scheme, and demonstrate that it is vulnerable to attacks such as password guessing and user impersonation. We also explain that the scheme does not verify the correctness of user’s input in the login phase, which is another design flaw. Then, we present an improved scheme and prove it secure in the random oracle model. [ABSTRACT FROM AUTHOR]

Chen et al. proposed a certificateless signcryption scheme without pairwise operation, which combined the private key and the public key of the encryption and decryption to generate a ciphertext encryption key. Under the random oracle model, it proved that the. scheme satisfies the indistinguishability under adaptive selective ciphertext attack and the unforgeability under adaptive selection message attack. This paper analyzed the security of Chen' s scheme and found that the scheme had a key leakage under the selective plaintext attack and an unforgeable attack that could not resist the malicious KGC. Therefore, this paper developed a new certificateless signcryption scheme based on the computational Diffie-Hellman problem and the discrete logarithm problem on the elliptic curve group. The new scheme avoids the security problem such as key leakage of the original scheme. Under the premise of ensuring security, the efficiency of the new scheme has not decreased. [ABSTRACT FROM AUTHOR]

The security of public-key encryption (PKE) schemes in a multi-user setting is aimed at capturing real-world scenarios in which an adversary could attack multiple users and multiple ciphertexts of its choice. However, the fact that a real-world adversary can also mount key-exposure attacks for a set of multiple public keys requires us to consider a more realistic notion of security in multi-user settings. In this study, we establish the security notion of PKE in a multi-user setting with corruptions, where an adversary is able to issue (adaptive) encryption, decryption, and corruption (i.e., private key) queries. We then propose the first practical PKE scheme whose security is proven in a multi-user setting with corruptions. The security of our scheme is based on the computational Diffie–Hellman (CDH) assumption and is proven to be tightly chosen-ciphertext secure in a random oracle model. Our scheme essentially follows the recently proposed modular approach of combining KEM and augmented DEM in a multi-user setting, but we show that this modular approach works well in a multi-user setting with corruptions. [ABSTRACT FROM AUTHOR]

Copyright of Journal of South China Normal University (Natural Science Edition) / Huanan Shifan Daxue Xuebao (Ziran Kexue Ban) is the property of Journal of South China Normal University (Natural Science Edition) Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As vehicle speed is fast and on board units' (OBUs) computing power, storage space, bandwidth and other resources are very limited, the efficiency of message transmission in vehicular ad hoc network is of great concern. Certificate‐based aggregate signature scheme provides a way to combine numerous signatures into one short signature. The authors propose a certificate‐based aggregate signature scheme for vehicular ad hoc networks. In this study, the authors prove that the proposed scheme is secure against forgery attack in the random oracle model and under the computational Diffie–Hellman problem. It is efficient and suitable for vehicular ad hoc networks. [ABSTRACT FROM AUTHOR]

A general multi-secret sharing (GMS) scheme allows a dealer to share multiple secrets among a set of participants, such that any authorized subset of participants can reconstruct the secrets simultaneously, while any unauthorized subset of participants cannot get any information about the secrets. The first formal security model of multi-stage secret sharing (MSS) schemes with a computational security proof in the random oracle model (ROM) had been introduced recently by Herranz et al. To the best of our knowledge, so far, there exists no computational secure GMS with a formal proof in ROM in the literature. This is what we will do in this paper. After describing formally the computational security of a GMS, we propose a GMS with adding a formal proof of computational security in ROM. [ABSTRACT FROM AUTHOR]

Recently, lattice signatures based on the Fiat‐Shamir framework have seen a lot of improvements which are efficient in practice. The security of these signature schemes depends mainly on the hardness of solving short integer solutions (SIS) and/or learning with errors problem in the random oracle model. The authors propose an alternative lattice‐based signature scheme on the Fiat‐Shamir framework over the ring Z[x]/(xn+1). The key generation in the signature scheme is based on the combination of NTRU and Ring SIS like key generation. Both the signature and the verification are done efficiently by doing polynomial convolutions in the ring Z[x]/(xn+1). The proposed signature scheme is provably secure based on the hardness of the Ring SIS problem in the random oracle model. The scheme is also efficient up to constant factors as the highly practical schemes which have provable secure instantiation. [ABSTRACT FROM AUTHOR]