A quantum blind signature scheme based on dense coding for non-entangled states

In some schemes, quantum blind signatures require the use of difficult-to-prepare multiparticle entangled states. By considering the communication overhead, quantum operation complexity, verification efficiency and other relevant factors in practical situations, this article proposes a non-entangled quantum blind signature scheme based on dense encoding. The information owner utilizes dense encoding and hash functions to blind the information while reducing the use of quantum resources. After receiving particles, the signer encrypts the message using a one-way function and performs a Hadamard gate operation on the selected single photon to generate the signature. Then the verifier performs a Hadamard gate inverse operation on the signature and combines it with the encoding rules to restore the message and complete the verification.Compared with some typical quantum blind signature protocols, this protocol has strong blindness in privacy protection,and higher flexibility in scalability and application. The signer can adjust the signature operation according to the actual situation, which greatly simplifies the complexity of the signature. By simultaneously utilizing the secondary distribution and rearrangement of non-entangled quantum states, a non-entangled quantum state representation of three bits of classical information is achieved, reducing the use of a large amount of quantum resources and lowering implementation costs. This improves both signature verification efficiency and communication efficiency while, at the same time, this scheme meets the requirements of unforgeability, non-repudiation, and prevention of information leakage.

Quantum circuit-based proxy blind signatures:A novel approach and experimental evaluation on the IBM quantum cloud platform

This paper presents a novel approach to proxy blind signatures in the realm of quantum circuits,aiming to enhance security while safeguarding sensitive information.The main objective of this research is to introduce a quantum proxy blind signature(QPBS)protocol that utilizes quantum logical gates and quantum measurement techniques.The QPBS protocol is constructed by the initial phase,proximal blinding message phase,remote authorization and signature phase,remote validation,and de-blinding phase.This innovative design ensures a secure mechanism for signing documents without revealing the content to the proxy signer,providing practical security authentication in a quantum environment under the assumption that the CNOT gates are securely implemented.Unlike existing approaches,our proposed QPBS protocol eliminates the need for quantum entanglement preparation,thus simplifying the implementation process.To assess the effectiveness and robustness of the QPBS protocol,we conduct comprehensive simulation studies in both ideal and noisy quantum environments on the IBM quantum cloud platform.The results demonstrate the superior performance of the QPBS algorithm,highlighting its resilience against repudiation and forgeability,which are key security concerns in the realm of proxy blind signatures.Furthermore,we have established authentic security thresholds(82.102%)in the presence of real noise,thereby emphasizing the practicality of our proposed solution.

A New ID-Based Proxy Blind Signature Scheme

An identity-based proxy blind signature scheme from bilinear pairings isintroduced, which combines the advantages of proxy signature and blind signature. Furthermore, ourscheme can prevent the original signer from generating the proxy blind signature, thus the profitsof the proxy signer are guaranteed. We introduce bilinear pairings to minimize computationaloverhead and to improve the related performance of our scheme. In addition, the proxy blindsignature presented is non-repudiable and it fulfills perfectly the security requirements of a proxyblind signature.

Fair quantum blind signatures

We present a new fair blind signature scheme based on the fundamental properties of quantum mechanics. In addition, we analyse the security of this scheme, and show that it is not possible to forge valid blind signatures. Moreover, comparisons between this scheme and public key blind signature schemes are also discussed.

Efficient ID-Based Proxy Blind Signature Scheme

In a proxy blind signature scheme, the proxy signer is allowed to generate a blind signature on behalf of the original signer. The proxy blind signature scheme is useful in several applications such as e-voting and e-payment. In this paper, we propose an identity-based proxy blind signature scheme which combines the advantages of proxy signature and of blind signature. Our scheme fulfills peffecdy the security requirements of a proxy blind signature. Comparing the previous scheme, our scheme needs less computational overhead and is more efficient.

A Proxy Blind Signature Scheme Based on DLP

A proxy signature scheme allows an original signer to delegate his signing capability to a proxy signer who can sign on behalf of the original signer. A blind signature is the concept with a salient feature that the signer can not make a linkage between the blind signature and the identity of the requester. Proxy signature and blind signature are used widely in electronic commerce. With satisfying the security properties of both two signatures, a new proxy blind signature scheme based on discrete logarithm problem is proposed.

Cryptanalysis of fair quantum blind signatures

We investigate the fair quantum blind signature scheme proposed by Wang and Wen [Wang T Y and Wen Q Y 2010 Chin. Phys. B 19 060307], which uses the fundamental properties of quantum mechanics and the availability of a trusted arbitrator. However, in this paper, we find that the protocol cannot satisfy the property of non-forgeability even under the condition that the trusted arbitrator is totally credible. Moreover, a simple feasible suggestion for improving the protocol is proposed.

Provably Secure Convertible Directed Partially Blind Signatures

Combining the concept of partially blind signature with the concept of directed signature, we introduce a new concept of convertible directed partially blind signature （CDPBS）, in which only the signer and the user can verify, confirm and disavow the validity of given signatures and convert given signatures into universally verifiable ones, to meet the need of signing personally or commercially sensitive messages. We give a formal definition of CDPBS and propose a concrete provably secure CDPBS scheme. The proposed scheme is efficient and secure, in which its unforgeability is the same as that of the Schnorr＇s signature scheme and its untransferability relies on the hardness of the decisional Diffie-Hellman problem. Furthermore, by letting the user＇s private key be a common constant, the proposed scheme can be used as a normal partially blind signature scheme.

Comment Fail-Stop Blind Signature Scheme Design Based on Pairings

Fail-stop signature schemes provide security for a signer against forgeries of an enemy with unlimited computational power by enabling the signer to provide a proof of forgery when a forgery happens. Chang et al proposed a robust fail-stop blind signature scheme based on bilinear pairings. However, in this paper, it will be found that there are several mistakes in Chang et al＇s fail-stop blind signature scheme. Moreover, it will be pointed out that this scheme doesn＇t meet the property of a fail-stop signature： unconditionally secure for a signer. In Chang et al＇s scheme, a forger can forge a valid signature that can＇t be proved by a signer using the ＂proof of forgery＂. The scheme also doesn＇t possess the unlinkability property of a blind signature.

Fair E-Payment Protocol Based on Simple Partially Blind Signature Scheme

This paper presents a simple partially blind signature scheme with low computation. By converse using the partially blind signature scheme, we build a simple fair e-payment protocol. In the protocol, two participants achieve the goals of exchanging their digital signatures from each other in a simple way. An ado vantage of this scheme is that this approach does not require the intervention of the third party in any case. The low-computation property makes our scheme very attractive for mobile client and smart-card implementation in many e-commerce applications.

An Efficient Threshold Blind Signature from Weil Pairing

Threshold blind signature is playing an important role in cryptography as well as in practical applications such as e-cash and e-voting systems, etc. In this paper, we present an efficient and practical threshold bind signature from Weil pairing on super-singular elliptic curves or hyper-elliptic curves over finite field and prove that our scheme is provably secure in the random oracle model.

An Efficient and Practical Quantum Blind Signature Protocol with Relaxed Security Model

Blind signature has a wide range of applications in the fields of E-commerce and block-chain because it can effectively prevent the blind signer from getting the original message with its blindness.Owing to the potential unconditional security,quantum blind signature(QBS)is more advantageous than the classical ones.In this paper,an efficient and practical quantum blind signature scheme relaxed security model is presented,where quantum superposition,decoy qubits and hash function are used for the purpose of blindness.Compared with previous QBS scheme,the presented scheme is more efficient and practical with a relaxed security model,in which the signer’s dishonest behavior can be detected other than being prevented as in other QBS schemes.

A New Anti-Quantum Proxy Blind Signature for Blockchain-Enabled Internet of Things

Blockchain technology has become a research hotspot in recent years with the prominent characteristics as public,distributed and decentration.And blockchain-enabled internet of things(BIoT)has a tendency to make a revolutionary change for the internet of things(IoT)which requires distributed trustless consensus.However,the scalability and security issues become particularly important with the dramatically increasing number of IoT devices.Especially,with the development of quantum computing,many extant cryptographic algorithms applied in blockchain or BIoT systems are vulnerable to the quantum attacks.In this paper,an anti-quantum proxy blind signature scheme based on the lattice cryptography has been proposed,which can provide user anonymity and untraceability in the distributed applications of BIoT.Then,the security proof of the proposed scheme can derive that it is secure in random oracle model,and the efficiency analysis can indicate it is efficient than other similar literatures.

A Novel Post-Quantum Blind Signature for Log System in Blockchain

In recent decades, log system management has been widely studied fordata security management. System abnormalities or illegal operations can befound in time by analyzing the log and provide evidence for intrusions. In orderto ensure the integrity of the log in the current system, many researchers havedesigned it based on blockchain. However, the emerging blockchain is facing significant security challenges with the increment of quantum computers. An attackerequipped with a quantum computer can extract the user's private key from thepublic key to generate a forged signature, destroy the structure of the blockchain,and threaten the security of the log system. Thus, blind signature on the lattice inpost-quantum blockchain brings new security features for log systems. In ourpaper, to address these, firstly, we propose a novel log system based on post-quantum blockchain that can resist quantum computing attacks. Secondly, we utilize apost-quantum blind signature on the lattice to ensure both security and blindnessof log system, which makes the privacy of log information to a large extent.Lastly, we enhance the security level of lattice-based blind signature under therandom oracle model, and the signature size grows slowly compared with others.We also implement our protocol and conduct an extensive analysis to prove theideas. The results show that our scheme signature size edges up subtly comparedwith others with the improvement of security level.

Publicly Verifiable Distributed Proxy Blind Signature Scheme

In this present paper, we propose a new proxy blind signature scheme, which is publicly verifiable distributed. The algorithm uses the idea of secret sharing schemes to distribute original signer＇s ability and the power of the proxy signer, and ensure the property of publicly verifiable secret sharing schemes. A new concept ＂verifiable time period＂ is also introduced to reduce the time cost in the period of verifications and increases the efficiency of our scheme.

A Fair Off-Line Electronic Cash Scheme Based on Restrictive Partially Blind Signature

A fair off-line electronic cash scheme was presented based on a provable secure restrictive par-tially blind signature. The scheme is more efficient than those of previous works as the expiry date and de-nomination information are embedded in the electronic cash, which alleviates the storage pressure for the bank to check double spending, and the bank need not use different public keys for different coin values, shops and users need not carry a list of bank抯 public keys to verify in their electronic wallet. The modular exponentiations are reduced for both the user and the bank by letting the trustee publish the public values with different structure as those of previous electronic cash schemes. The scheme security is based on the random oracle model and the decision Diffie-Hellman assumption. The scheme can be easily extended to multi-trustees and multi-banks using threshold cryptography.

A Proxy Blind Signature Scheme and an Off-Line Electronic Cash Scheme

To support withdrawing and storing money from all levels of the bank for the customers in the real world, in this paper, we propose a proxy blind signature scheme and an off-line e-cash scheme based on the new proxy blind signature scheme. The pro- posed proxy blind signature is proven secure in the random oracle model under chosen-target computational Diffie-Hellman assump- tions, and the e-cash scheme can satisfy the security requirements of unforgeability, anonymity, and traceability.

Provably secure robust threshold partial blind signature

Threshold digital signature and blind signature are playing important roles in cryptography as well as in practical applications such as e-cash and e-voting systems. Over the past few years, many cryptographic researchers have made considerable headway in this field. However, to our knowledge, most of existing threshold blind signature schemes are based on the discrete logarithm problem. In this paper, we propose a new robust threshold partial blind signature scheme based on improved RSA cryptosystem, This scheme is the first threshold partial blind signature scheme based on factoring, and the robustness of threshold partial blind signature is also introduced. Moreover, in practical application, the proposed scheme will be especially suitable for blind signature-based voting systems with multiple administrators and secure electronic cash systems to prevent their abuse.

Fair e-payment protocol based on blind signature

Electronic transaction through e-payment protocol will grow tremendous in the coming years. In this article, by conversely using blind signature, the authors propose a fair electronic payment scheme for electronic commerce, which can ensure two participants＇ right simultaneously in electronic transaction process. This scheme is different from other existing schemes and it does not require strong trust relation between customer and merchant. In the scheme, a semi-trusted third party （S-TTP） is involved to provide a fair commerce environment. The S-TTP takes part in the protocol on-line and no secure information about the business is leaked. Moreover, the participants do not need to register to S-TTP. This scheme does not require intervention of a third party in case of dispute, if one user cheats or simply crashes.

Efficient Privacy Enhanced Software Registration with ID-Based Blind Signatures

In existing software registration schemes, the privacy of users is not taken into account and may be in the risks of abuses. In this paper, we proposed a novel software registration system which can greatly reduce unauthorized use of software while keeping the privacy of users. To the best of our knowledge, this is the first system that the privacy of users is guaranteed in software registration. Our system enjoys a modular design and can be implemented by any secure ID-based partially blind signature scheme. Furthermore, the proposal allows flexible registration information definition. This feature makes our scheme flexible and practical for more software registration applications.