Proposed Signature Scheme Research Articles

PIMA: A Privacy-preserving Identity management system based on an unlinkable MAlleable signature

This paper presents a privacy-preserving identity management system, referred to as Pima. The proposed system is built over a novel unlinkable malleable signature scheme, called UMS. Pima supports pseudonymity, as it is more in line with today’s web service interactions than anonymity. The originality of the approach is manifold. First, Pima satisfies both users’ and providers’ basic security and privacy needs as it provides a user centric approach which permits the users to keep control over their revealed attributes, and the service providers to get attributes certified by an identity provider and associated with different pseudonymous sessions. Second, Pima helps service providers to comply with the data minimization principle required by the E.U. General Data Protection Regulation, through the enforcement of both sanitizable and redactable features. Third, the proposed signature scheme UMS fulfills main security and strong privacy requirements at a constant pairing computation overhead. Fourth, Pima’s concrete construction is proven as secure under the generic group model. Fifth, the implementation results demonstrate high efficiency w.r.t. most closely related work, while considering resource-constrained devices, i.e., Android-10 smartphone.

A New Lattice-Based Blind Ring Signature for Completely Anonymous Blockchain Transaction Systems

Blockchain technology has been widely applied in numerous industries with its decentralization, verifiability, distributivity, and immutability. However, the identity privacy security of blockchain users is facing serious threats because of the openness of traditional blockchain transaction information. Moreover, numerous traditional cryptographic algorithms used by blockchain transaction networks are difficult to attack quantum computing. In this paper, we propose a new lattice-based blind ring signature scheme in allusion to completely anonymous blockchain transaction systems. There into, the blind ring signature can implement the complete anonymity of user identity privacy in blockchain transactions. Meanwhile, lattice cryptography can availably resist quantum computing attacks. Firstly, the proposed signature scheme has strong computational security based on the small integer solution (SIS) problem and a high sampling success rate by utilizing the techniques of rejection sampling from bimodal Gaussian distribution. Secondly, the proposed signature scheme can satisfy the correctness and security under the random oracle model, including anonymity, blindness, and one-more unforgeability. Thirdly, we construct a blockchain transaction system based on the proposed blind ring signature algorithm, which realizes the completely anonymous and antiquantum computing security of the blockchain users’ identity privacy. Finally, the performance evaluation results show that our proposed blind ring signature scheme has lower latency, smaller key size, and signature size than other similar schemes.

Constructing New Collective Signature Schemes Base on Two Hard Problems Factoring and Discrete Logarithm

In network security, digital signatures are considered a basic component to developing digital authentication systems. These systems secure Internet transactions such as e-commerce, e-government, ebanking, and so on. Many digital signature schemes have been researched and published for this purpose. In this paper, we propose two new types of collective signature schemes, namely i) the collective signature for several signing groups and ii) the collective signature for several individual signings and several signing groups. And then we used two difficult problems factoring and discrete logarithm to construct these schemes. To create a combination of these two difficult problems we use the prime module p with a special structure: p = 2n +1. Schnorr's digital signature scheme is used to construct related basic schemes such as the single signature scheme, the collective signature scheme, and the group signature scheme. The proposed collective signature schemes are built from these basic schemes. The proposed signature scheme is easy to deploy on existing PKI systems. It can support PKIs in generating and providing a unique public key, a unique digital signature, and a unique digital certificate for a collective of many members. This is essential for many collective transactions on today's Internet.

Blockchain-Based Mutual Authentication Protocol with Privacy Protection in Telemedicine

Telemedicine builds a patient-centered remote diagnosis and continuous monitoring service system, which can effectively alleviate the current situation of difficult and expensive medical treatment. This paper focuses on mutual authentication with privacy protection in telemedicine. First, we propose a decentralized multi-authority attribute-based signature scheme. The signature scheme can be used to verify the signer’s attributes without leaking the identity information, thereby achieving privacy protection while authenticating. Combined with the proposed signature scheme, a blockchain-based mutual authentication protocol with privacy protection in telemedicine is designed. By this protocol, patients and telemedicine terminal can encrypt and store the medical data off-chain, and store the data digest and decentralized attribute-based signature on the blockchain. As a result, the confidentiality of the data and the authenticity of the source can be guaranteed. In addition, the nature of the blockchain and signature ensure that accurate liability determination can be made when medical disputes occur. Theoretical analysis shows that our protocol is secure and practical.

A secure and efficient group signature scheme based on multivariate public key cryptography

Group signatures are significant primitive for anonymity, which allow group members to sign messages while hiding in the group, however, the signers remain accountable. Most of the existing schemes on group signature are relying on traditional cryptographic primitives, whereas rapid advancements in quantum computing suggest an originating threat to usual cryptographic primitives. This makes the necessity of quantum computer resistant cryptographic primitives. Multivariate public key cryptography (MPKC) is one of the promising options that may withstand quantum attacks. Its constructions are potential candidates for post-quantum (PQ) cryptography as they are very fast and require only modest computational resources. There are many existing secure and practical multivariate digital signatures. However, there is a deficiency of more advanced multivariate group signature scheme. The existing multivariate group signature has weaknesses in terms of security and efficiency. This paper introduces a new multivariate group signature scheme employing a 5-pass identification protocol and multivariate signature scheme as its building blocks. The proposed signature scheme possesses unforgeability, user’s anonymity, unlinkability, exculpability and traceability property. Unlike most of the existing post-quantum group signatures, the sizes of the signatures and the public parameters are not dependent on the number of group users in our construction. It depends only on the security parameters. In particular, our construction is the first MPKC based group signature, where signature size and public parameter size are independent of the number of group users.

Lattice signatures using NTRU on the hardness of worst‐case ideal lattice problems

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 . 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 . 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.

Edge Computing-Based Privacy-Preserving Authentication Framework and Protocol for 5G-Enabled Vehicular Networks

Based on the functional characteristics of inter-vehicle communication networks under the current framework, a privacy-preserving authentication framework that combines fifth-generation communication technology (5G) and edge computing technology is proposed. The proposed framework is different from that used in the previous 802.11p-based inter-vehicle communication network architecture, and we use device-to-device technology to achieve communication between vehicles. One difference between a 5G-enabled model and a traditional model for vehicle ad hoc networks is that secure communication between vehicles in a 5G-enabled model is challenging. The authentication protocol proposed in this study can be divided into two parts. The first part involves authenticating and selecting an edge computing vehicle, wherein a fuzzy logic mathematical method is used in the selection process. The second part is the mutual authentication between edge computing and ordinary vehicles. In this process, the exchange of security information between vehicles in a group is possible. Simultaneously, the identity privacy and traceability of the vehicle are ensured. Moreover, the proposed signature scheme is proved to be secure under a random oracle model. Performance evaluation results demonstrate that our proposed scheme has relatively lower computational and communication overhead than existing schemes.

A public key cryptosystem and signature scheme based on numerical series

A public key cryptosystem and signature scheme based on a proposed key exchange algorithm are introduced. The key exchange algorithm is based on the difficulty of calculating the nth partial sum of infinite numerical series where no exponentiation computation is required to share a secret key between two parties as in the Diffie–Hellman algorithm. With the proposed public key cryptosystem ciphering and deciphering of messages, online signing documents and verifying signatures do not require exponentiation computation while providing higher security level than the state-of-the-art cryptosystems that depend on the difficulty of discrete logarithmic problem or factorizing large prime numbers. The proposed cryptosystem and signature scheme do not depend on elliptic curve cryptography or RSA cryptography that are computationally too slow, this makes the proposed cryptosystem and signature scheme computationally faster, easier to implement and more practical to be used in online transactions. It also provides a higher level of security as it provides forward secrecy and using large size symmetric keys to encrypt and decrypt messages in a significantly short time. Moreover, the proposed signature scheme can be used as a cryptographic hash function as the hash value significantly changes when a single letter in the document is changed. In comparison with the state-of-the art the experimental results show the superiority of the proposed key exchange algorithm and public key cryptosystem.

Modified pqsigRM: RM Code-Based Signature Scheme

We present a novel code-based signature scheme called modified pqsigRM. This scheme is based on a modified Reed–Muller (RM) code, which reduces the signing complexity and key size compared with existing code-based signature schemes. In fact, it strengthens pqsigRM submitted to NIST for post-quantum cryptography standardization. The proposed scheme has the advantage of the pqsigRM decoder and uses public codes that are more difficult to distinguish from random codes. We use $(U,U+V)$ -codes with the high-dimensional hull to overcome the disadvantages of code-based schemes. The proposed decoder samples from coset elements with small Hamming weight for any given syndrome and efficiently finds such an element. Using a modified RM code, the proposed signature scheme resists various known attacks on RM-code-based cryptography. For 128 bits of classical security, the signature size is 4096 bits, and the public key size is less than 1 MB.

New number-theoretic cryptographic primitives

AbstractThis paper introduces new prq-based one-way functions and companion signature schemes. The new signature schemes are interesting because they do not belong to the two common design blueprints, which are the inversion of a trapdoor permutation and the Fiat–Shamir transform. In the basic signature scheme, the signer generates multiple RSA-like moduli ni = pi2qi and keeps their factors secret. The signature is a bounded-size prime whose Jacobi symbols with respect to the ni’s match the message digest. The generalized signature schemes replace the Jacobi symbol with higher-power residue symbols. Given of their very unique design, the proposed signature schemes seem to be overlooked “missing species” in the corpus of known signature algorithms.

An Efficient and Secure Pairing Free Short ID-Based Signature Scheme over Elliptic Curve

The cost of pairing computation is much more than the cost of computing scalar multiplication over elliptic curve group. Hence, the bilinear pairing based digital signature are less practical in the applications where short signature length as well as fast signature generation and verification are required. For such type of applications, we present a pairing computation free efficient and secure short identity (ID)-based signature scheme over elliptic curve. The proposed signature scheme is unforgeable in ROM against existential forgery on adaptive chosen message and ID attack with the assumption that ECDLP is hard in G. Moreover, the proposed signature scheme uses general cryptographic hash function in spite of costly map-to-point hash function and the comparative performance analysis shows that the proposed scheme is much more efficient, secure and short in signature length from related ID-based signature schemes

A Third-Party Mobile Payment Scheme Based on NTRU Against Quantum Attacks

Mobile devices now serve to pay for goods and services by means of the transmission of data, a system known as mobile payments. Mobile payment is receiving growing attention globally, from consumers to merchants, as an alternative to using cash, check, or credit cards. Most encryption techniques applied in mobile payment are based on traditional public key infrastructure. However, the traditional public key encryption algorithm has higher requirements for hardware, which is not suitable for mobile terminals of limited computing resources. In addition, these public key encryption algorithms are vulnerable to quantum computing attacks and the availability of practical quantum computer is approaching faster than previously believed. Since mobile payment is facing more and more security issues, how to complete the payment process effectively and securely becomes a problem urgently to be solved. In this paper, we firstly analyze the problem of the signature scheme for mobile payment and propose an improved signature scheme based on the Number Theory Research Unit (NTRU). The results of the experiment show that the proposed signature scheme is secure and efficient which can raise the speed and probability of generating reasonable signature value. Second, we introduce a new public key infrastructure NTRU-WPKI and design a third-party mobile payment model based on NTRU-WPKI to increase the efficiency and security. Finally, by doing the overall simulation, we prove that our model is highly effective and secure.

Lattice-based identity-based ring signature without trapdoors

So far, most ring signature schemes rely on hard number theory problems, such as discrete logarithm, bilinear pairings and so on. Unfortunately, the above underlying number theory problems will be solvable in the post quantum era. Lattice-based cryptography is a hotspot of research recently, due to its implementation simplicity and provable security reductions. When the hash-and-sign signature scheme was constructed based on the hardness of worst-case lattice problems, provably secure lattice-based ring signature schemes were finally constructed. However, the hash-and-sign ring signatures were rather inefficient (with megabytes long signatures). In this paper, we propose an alternative method for constructing lattice-based and identity-based ring signature scheme which does not use the hash-and-sign methodology. In the random oracle model, the proposed signature scheme based on the problem in general lattices is unforgeable and holds anonymity. Compared with the previous instantiations of the hash-and-sign ring signature schemes, the lengths of secret key, public key and signatures in the proposed scheme are much shorter. The signing algorithm is quite simple, with matrix-vector multiplications and rejection samplings.

Probably Secure Efficient Anonymous Credential Scheme

This article describes how after the concept of anonymous credential systems was introduced in 1985, a number of similar systems have been proposed. However, these systems use zero-knowledge protocols to authenticate users, resulting in inefficient authentication during the stage of proving credential possession. To overcome this drawback, this article presents a signature scheme that uses partially blind signatures and chameleon hash functions such that both the prover and verifier achieve efficient authentication. In addition to providing a computational cost comparison table showing that the proposed signature scheme achieves a more efficient credential possession proving compared to other schemes, concrete security proofs are provided under a random oracle model to demonstrate that the proposed scheme satisfies the properties of anonymous credentials.

Cryptanalysis and improvement of a ECDLP based proxy blind signature scheme

The proxy blind signature scheme (PBSS), allows the authorized proxy signer to use his proxy private key to create a legal blind signature on behalf of original signer. Recently, Alghazzawi, Salim and Hasan (A-S-H), presented the elliptic curve cryptography (ECC) based PBSS. However, we found their scheme is vulnerable to a linkability attack, which shows that there was lacked of unlinkability. In this paper, the improvements are being done in this regards in such a manner that the proposed signature scheme satisfies all the security properties, including unlinkability property. The security of the proposed PBSS rely on the elliptic curve discrete logarithm problem (ECDLP). The signature scheme presented can be implemented in low power and small processor device such as smart card.

Demonstrably Secure Signature Scheme Resistant to k-Traitor Collusion Attack

This paper presents the proposal of a new implicit and explicit certificate-based signature scheme (IE-CBS-kCAA scheme) using Sakai–Kasahara’s type keys. The scheme security depends on the computational difficulty of solving the modified collusion attack algorithm with ${k}$ traitors ( ${k}$ -mCAA problem), reducible in particular cases to the known ${k}$ -CAA problem. The originality of the scheme consists not only in the formulation and application of a new difficult computational problem but also in its design to meet the paradigm of public key cryptography based on implicit and explicit certificates. Due to such an approach, the proposed signature scheme can be used in the traditional public key infrastructure with the revocation of explicit certificates and in non-standard infrastructures without the revocation of implicit certificates. In this paper, the security model is formulated and it is shown that the IE-CBS-kCAA signature scheme is existentially unforgeable against adaptively chosen messages in the random oracle model. Moreover, it results from the comparison of the IE-CBS-kCAA scheme with other signature schemes based on implicit and/or explicit certificates that its computational efficiency is at a similar level. Computational tests have also shown that the scheme can be used in practice.

A Secure Cryptocurrency Scheme Based on Post-Quantum Blockchain

Nowadays, blockchain has become one of the most cutting-edge technologies, which has been widely concerned and researched. However, the quantum computing attack seriously threatens the security of blockchain, and related research is still less. Targeting at this issue, in this paper, we present the definition of post-quantum blockchain (PQB) and propose a secure cryptocurrency scheme based on PQB, which can resist quantum computing attacks. First, we propose a signature scheme based on lattice problem. We use lattice basis delegation algorithm to generate secret keys with selecting a random value, and sign message by preimage sampling algorithm. In addition, we design the first-signature and last-signature in our scheme, which are defined as double-signature. It is used to reduce the correlation between the message and the signature. Second, by combining the proposed signature scheme with blockchain, we construct the PQB and propose this cryptocurrency scheme. Its security can be reduced to the lattice short integer solution (SIS) problem. At last, through our analysis, the proposed cryptocurrency scheme is able to resist the quantum computing attack and its signature satisfies correctness and one-more unforgeability under the lattice SIS assumption. Furthermore, compared with previous signature schemes, the sizes of signature and secret keys are relatively shorter than that of others, which can decrease the computational complexity. These make our cryptocurrency scheme more secure and efficient.

Secure and Efficient Signature Scheme Based on NTRU for Mobile Payment

Mobile payment becomes more and more popular, however the traditional public-key encryption algorithm has higher requirements for hardware which is not suitable for mobile terminals of limited computing resources. In addition, these public-key encryption algorithms do not have the ability of anti-quantum computing. This paper researches public-key encryption algorithm NTRU for quantum computation through analyzing the influence of parameter q and k on the probability of generating reasonable signature value. Two methods are proposed to improve the probability of generating reasonable signature value. Firstly, increase the value of parameter q. Secondly, add the authentication condition that meet the reasonable signature requirements during the signature phase. Experimental results show that the proposed signature scheme can realize the zero leakage of the private key information of the signature value, and increase the probability of generating the reasonable signature value. It also improve rate of the signature, and avoid the invalid signature propagation in the network, but the scheme for parameter selection has certain restrictions.

Short Signatures from Diffie–Hellman: Realizing Almost Compact Public Key

In this paper, we present a new digital signature scheme based on the computational Diffie---Hellman (CDH) assumption in the standard model. The proposed signature scheme is not only asymptotically almost compact but also practical for concrete parameters in the sense that the public key has 29 group elements, and the signature consists of two group elements and two exponents for 80-bit security. Note that the Waters signature scheme, which is the previous best digital signature scheme in the same category (CDH assumption, standard model), requires linear-sized public keys in the security parameter, particularly those with 164 group elements for 80-bit security. To achieve our goal, we revisited the CDH-based signature scheme proposed by Hohenberger and Waters (EUROCRYPT 2009), which is a stateful signature scheme but achieves asymptotically compact parameters in the sense that its public key and signature consist of constant group elements. We modify the Hohenberger---Waters signature scheme to remove the state information from the signatures. More precisely, we use programmable hashes and random tags, instead of counters which is the state information maintained by a signer. To prove the security of the proposed signature scheme, we developed prefix-guessing technique for random tags. Note that the prefix-guessing technique was first introduced by Hohenberger and Waters (CRYPTO 2009) and was originally used for message queries.

CRYPTANALYSIS AND IMPROVEMENT OF A PROXY SIGNATURE WITH MESSAGE RECOVERY USING SELF-CERTIFIED PUBLIC KEY

Combining the concept of self-certified public key and message recovery, Li-Zhang-Zhu (LZZ) gives the proxy signature scheme with message recovery using self-certified public key. The security of the proposed scheme is based on the discrete logarithm problem (DLP) and one-way hash function (OWHF). Their scheme accomplishes the tasks of public key verification, proxy signature verification, and message recovery in a logically single step. In addition, their scheme satisfies all properties of strong proxy signature and does not use secure channel in the communication between the original signer and the proxy signer. In this paper, it is shown that in their signature scheme a malicious signer can cheat the system authority (SA), by obtaining a proxy signature key without the permission of the original signer. At the same time malicious original signer can also cheat the SA, he can also obtain a proxy signature key without the permission of the proxy signer. An improved signature scheme is being proposed, which involves the remedial measures to get rid of security flaws of the LZZ et al.'s. The security and performance analysis shows that the proposed signature scheme is maintaining higher level of security, with little bit of computational complexity.