Blind Signature Research Articles

Unforgeability of Blind Schnorr in the Limited Concurrency Setting

Blind signature schemes enable a user to obtain a digital signature on a message from a signer without revealing the message itself. Among the most fundamental examples of such a scheme is blind Schnorr, but recent results show that it does not satisfy the standard notion of security against malicious users, One-More Unforgeability (OMUF), as it is vulnerable to the ROS attack. However, blind Schnorr does satisfy the weaker notion of sequential OMUF, in which only one signing session is open at a time, in the Algebraic Group Model (AGM) + Random Oracle Model (ROM), assuming the hardness of the Discrete Logarithm (DL) problem. This paper serves as a first step towards characterizing the security of blind Schnorr in the limited concurrency setting. Specifically, we show that blind Schnorr satisfies OMUF when at most two signing sessions can be concurrently open (in the AGM+ROM, assuming DL). Our argument suggests that it is plausible that blind Schnorr satisfies OMUF for up to polylogarithmically many concurrent signing sessions. Our security proof involves interesting techniques from linear algebra and combinatorics.

Recovery of Accidental Traumatic Brain Injury (TBI) in an Infant Bonnet Macaque (Macaca radiata) by Progesterone Therapy

An infant male bonnet macaque with a history of accident and lateral recumbency presented to the Veterinary Clinical Complex, VCRI, Orathanadu. On examination he scored a 10 on the modified Glasgow Coma Scale (GCS), and the animal had racoon eyes. Immediately skull X-ray was taken and it revealed two radiating temporal bone fracture. These characteristics strongly pointed to a tentative diagnosis of Traumatic Brain Injury. In addition to supportive care, Progesterone, a neuroprotective steroid, was continuously administered to the animal at a dose rate of 0.2 mg per kg SID P.O. In order to manage and monitor the animal health, it was admitted to the critical care unit. On the tenth day, the animal showed slight improvement and had hemiparesis on the contralateral side of the cranial lesion. The animal's limb reflexes were fully restored by day 20. However cerebral and vestibular lesions persisted with signs of blindness, nystagmus, and circling. After 60 days of continuous treatment animal recovered uneventfully.

CSI-Otter: isogeny-based (partially) blind signatures from the class group action with a twist

In this paper, we construct the first provably-secure isogeny-based (partially) blind signature scheme. While at a high level the scheme resembles the Schnorr blind signature, our work does not directly follow from that construction, since isogenies do not offer as rich an algebraic structure. Specifically, our protocol does not fit into the linear identification protocol abstraction introduced by Hauck, Kiltz, and Loss (EUROCYRPT’19), which was used to generically construct Schnorr-like blind signatures based on modules such as classical groups and lattices. Consequently, our scheme is provably secure in the random oracle model (ROM) against poly-logarithmically-many concurrent sessions assuming the subexponential hardness of the group action inverse problem. In more detail, our blind signature exploits the quadratic twist of an elliptic curve in an essential way to endow isogenies with a strictly richer structure than abstract group actions (but still more restrictive than modules). The basic scheme has public key size 128 B and signature size 8 KB under the CSIDH-512 parameter sets—these are the smallest among all provably secure post-quantum secure blind signatures. Relying on a new ring variant of the group action inverse problem (rGAIP\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ extsf{rGAIP}$$\\end{document}), we can halve the signature size to 4 KB while increasing the public key size to 512 B. We provide preliminary cryptanalysis of rGAIP\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ extsf{rGAIP}} $$\\end{document} and show that for certain parameter settings, it is essentially as secure as the standard GAIP\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ extsf{GAIP}$$\\end{document}. Finally, we show a novel way to turn our blind signature into a partially blind signature, where we deviate from prior methods since they require hashing into the set of public keys while hiding the corresponding secret key—constructing such a hash function in the isogeny setting remains an open problem.

Commercial Applications of Electronic Currencies

Digital payment systems, also known as digital money, digital currency, or electronic money, have come a long way since the invention of computer-based communication systems. From the requirement of human-to-machine monetary transactions, it has evolved. E-money is a virtual cash model that is making its way in the online and virtual transfer domain. The authorization transaction is conducted through traditional banking systems between the payer and the payee, which issues e-money accounts for these transactions. After this amount is booked and stored by banks, it can be verified and transferred to payers/payees as e-money. One important challenge in this domain is to reduce reliance on the identifying authority, and the corresponding e-money transactions should be as simple and secure as cash transactions. Bitcoin – the electronic currency introduced in 2009 by an anonymous author and designed to work independently of a central authority – is unique and often considered news. This ignores the general history of electronic currencies. In 1998, Wei Dai introduced B-money, an efficient product of minimizing communication that serves as a method of fees and rewards for providing limited resources. Also in 1998, Adam Back introduced Hashcash – a currency that ties real computing costs to solve increasingly difficult computational puzzles. In 1999, Nick Szabo introduced bit gold – a product offering small chained proof of work and conducted via broadcast. David Chaum’s eCash, based on blind signatures, was a technical principle in the paper in 1983, and in 1990 with Amos Fiat and Moni Naor in addition known as related technology.

A blockchain-based hybrid encryption technique with anti-quantum signature for securing electronic health records

Electronic health records (EHRs) are important for the efficient management of healthcare data. However, Healthcare data travels across an open route, i.e., the Internet, making EHR security a difficult process to do. This puts healthcare data vulnerable to cyber assaults. A possible method for protecting EHRs is blockchain technology. In this work, we develop an EHR architecture based on blockchain, which ensures all stakeholder's safety and privacy. We analyze various security architectures used for EHRs and the standard encryption system is integrated with quantum computing (QC). To safeguard the conventional traditional encrypting system against quantum assaults, we provide a hybrid signature technique that combines the Elliptic Curve Digital Signature Algorithm (ECDSA) and Dilithium within the anti-quantum lattice-based blind signature. Based on the difficulty of lattice problems over finite fields, Dilithium is a lattice-based signature method that is substantially safe against selected message assaults. The developed technique creates high entropy secret keys using the lattice basis delegation mechanism. The combination of ECDSA and Dilithium provides an efficient and secure signature system that is resilient to quantum attacks. The proposed scheme ensures that only authorized users with a defined role can use the database to access the data. We evaluate the efficiency of our scheme by comparing its performance to other state-of-the-art solutions in terms of transaction throughput, resource utilization, and communication cost. Results demonstrate that the developed technique outperforms the existing techniques in terms of efficiency and security.

A new quantum group blind signature scheme based on GHZ states

With the development of quantum computers, traditional communication security based on classical computers can no longer guarantee unconditional security. At the same time, a series of encrypted communication solutions that rely on quantum mechanical properties have been spawned. This article focuses on the field of quantum signatures, based on the entangled Greenberger–Horne–Zeilinger state, combining group signatures (any member of the group can sign on behalf of the group) and blind signatures (the signer cannot know the accuracy of the signature content) proposed a new quantum group blind signature scheme that utilizes quantum key distribution to achieve unconditional security. By splitting the original message, the scheme strengthens the relevance of the signature participants and makes the signature to have stronger binding. Then, the security of the scheme against internal and external attacks is analyzed. In this scheme, a pleasing efficiency has been achieved, and the non-repudiation of signatures has been enhanced. At the same time, disputed signatures can be traced back to the signer.

A novel quantum multiparty blind signature scheme based on χ state

Quantum digital signature, as an extension of classical digital signature, has become an important research content in quantum cryptography. Quantum blind signature combines the advantages of classical blind signature and quantum signature, which can ensure the unconditional security of the scheme based on the realization of the blinded signature of the message, and can be effectively applied in many real-world scenarios. This paper uses the four-particle [Formula: see text] state as a communication channel, combined with quantum teleportation technology to propose a new quantum multi-party blind signature protocol, which has the following characteristics: First, the Toeplitz hash function based on the linear shift register is introduced to blind the message, and the length of the blinded message can be adjusted according to the actual demand to increase the flexibility of the scheme; Second, through multi-party participation, the blind signature of multi-bit messages can be realized, and the signature efficiency can be improved. Compared with other quantum blind signatures, the signature efficiency has been greatly improved; Finally, using the four-particle [Formula: see text] state as a quantum channel can make the scheme use fewer resources to transmit data and increases the security of the scheme. Through security analysis, it can be seen that the scheme has blindness, nonrepudiation and unforgeability.

A new lattice-based partially blind signature with more complete proof

Partially blind signatures are introduced on the basis of blind signatures, which not only retain the advantages of blind signatures, but also solve the contradiction between anonymity and controllability in blind signatures. With the development of quantum computing technology, it becomes more urgent to construct secure partially blind signature schemes in quantum environments. In this paper, we present a new partially blind signature scheme and prove the security under the Ring-SIS assumption in the random oracle model. To avoid the restart problem of signature schemes caused by rejection sampling, a large number of random numbers are sampled in advance, so that they only need to be re-selected at the current stage without terminating the whole signature process when the conditions are not met. In addition, the hash tree technology is used to reduce communication costs and improve interactive performance. In order to avoid the errors in the security proof of the previous scheme, our proof builds upon and extends the modular framework for blind signatures of Hauck et al. and the correctness, partial blindness, and one-more unforgeability of the scheme are proved in detail according to the properties of the linear hash function.

Blockchain assisted blind signature algorithm with data integrity verification scheme

SummaryAs the demand for cloud storage systems increases, ensuring the security and integrity of cloud data becomes a challenge. Data uploaded to cloud systems are vulnerable to numerous sorts of assaults, which must be handled appropriately to avoid data tampering issues. In addition, quantum computers are expected to be introduced soon, which may face multiple security issues by destroying all traditional cryptosystems. This work introduces a quantum‐resistant blockchain centered data integrity verification system with the use of several techniques. Initially, the keys and signatures are generated by the users with the help of the lattice‐based blind signature algorithm (L_BSA), which is a combination of lattice cryptography and a blind signature algorithm. From the generated random keys, the most optimal key is then selected by the Puzzle Optimization Algorithm (POA), which is then made available to the encryption phase. Then, the upgraded Merkle tree‐assisted vacuum filter (Vac‐UMT) algorithm is executed to accomplish the encryption task. Then the data are converted into blocks using blockchain technology and uploaded to the cloud. When receiving the audit requests, the verification process is carried out, and the evidence report is generated for the users. The proposed work is simulated in JAVA and assessed with the UNSW‐NB15 dataset, and the outcomes demonstrated that the system is highly efficient and secure.

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.

Semi-quantum blind double signature scheme with semi-trusted arbitrator

In order to solve the security of electronic transactions on limited goods, some quantum blind double signature (QBDS) protocols were proposed. In existing QBDS protocols, all participants must have specific quantum computing capabilities. Realistically, high cost of quantum devices may hinder people from using the QBDS protocol. Therefore, we propose a semi-quantum arbitrator blind double signature (SQABDS) scheme. In this scheme, the sender (signer) and the receiver both are classical participants, which can relatively reduce the dependence on quantum hardware. The introduction of blind signers can protect the privacy of electronic transactions, the introduction of semi-trusted arbitrator can relax the strong assumption about the trustworthiness of the arbitrator, for the arbitrator cannot forge the signature. In addition, the SQABDS scheme can be used to sign classical messages directly without performing any quantum swapping tests or quantum gate operations. Finally, the analysis shows that our scheme is securer and its quantum cost is relatively lower.

Semiquantum proxy blind signature based on quantum teleportation

Semiquantum proxy blind signature based on quantum teleportation

Quantum Circuit-Based Proxy Blind Signatures: A Novel Approach and Experimental Evaluation on the IBM Quantum Cloud Platform

Abstract 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 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, 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 public-key quantum group blind signature scheme based on single-qubit rotations

With the continuous development of quantum technology, the quantum signature as an application of quantum cryptography has received great attention. In this paper, we propose a public-key quantum group blind signature scheme based on single-qubit rotations. In this scheme, the group manager generates a public key. Each group member randomly generates his own private key according to the public key. The signer uses his private key and random sequence to generate the signature. The verifier uses the public key to verify the correctness of the quantum signature. The public and private keys can be reused, which simplifies the key management of the signature system. In this scheme, the random sequence is used to enhance the security of the scheme. At the same time, the quantum efficiency is improved by using single-qubit rotations. The security analysis shows that our scheme can ensure the security of the keys, the unforgeability and the non-deniability of the signature.

A blind signature scheme for IoV based on 2D-SCML image encryption and lattice cipher

Today’s Internet of Vehicles (IoV) faces many security risks in the data transmission process, and image data is more vulnerable to security threats in the transmission process due to its special characteristics such as large amounts of information and high visibility. Therefore, to guarantee the dependability of data transmission in the IoV environment, this paper designs a blind signature scheme for IoV based on two-dimensional sine cosine cross-chaotic mapping (2D-SCML) image encryption and lattice cipher (BSS-IoV). The innovation of this scheme is that it aims at blind signature of image information, blinds it before sending the information, and combines the lattice public key encryption algorithm to better ensure the safe and reliable transmission of information and reduce the risk of information disclosure. To further ensure the security of the scheme, an image encryption algorithm based on 2D-SCML and pixel splitting (2PS-IEA) is proposed, which is used to blind the information and thus reduce the risk of information leakage on the one hand, on the other hand, it is used in the signature process to ensure the security of the signed information. The 2D-SCML is derived from the cross-model structure proposed in this paper. Through simulation results and experimental analysis, the values of NPCR and UACI, respectively, 99.6094% and 33.4635%, are close to ideal values. And 50% of the cut image can also recover the rough information, which indicates that the signature scheme has the security against differential attacks, cut attacks and noise attacks. Moreover, the security analysis shows that the scheme has the anti-tamper, anti-repudiation and traceability.

A novel chaotic map partially blind signature scheme based on quadratic residue problems

A novel chaotic map partially blind signature scheme based on quadratic residue problems

Blind signature as a shield against backdoors in smart cards

The problem of signature forgery (including signature key recovery) in the presence of backdoors in the hardware or software of functional key carriers (smart cards) is considered. A new approach to solving the problem based on using blind signature schemes is proposed. It is shown that honest-signer blindness and honest-but-curious unforgeability of the blind signature schemes imply security against backdoors in smart cards. As a concrete example, we consider a blind version of the GOST signature scheme (the blind signature scheme proposed by Camenisch) and show that this scheme is resistant to backdoors under the single assumption that GOST is secure in the standard sense.

A secured lightweight authentication protocol for vehicular ad hoc network using blind signature

A secured lightweight authentication protocol for vehicular ad hoc network using blind signature

An Efficient Certificateless Key-Insulated Blind Signature Scheme Based on Smart Contract for Data Sharing in Industrial Internet of Things

An Efficient Certificateless Key-Insulated Blind Signature Scheme Based on Smart Contract for Data Sharing in Industrial Internet of Things

О свойстве неподделываемости схемы подписи вслепую Шаума - Педерсена

The paper is devoted to the analysis of the unforgeability property of the Chaum - Pedersen blind signature scheme in case an adversary is able to initiate parallel sessions of the signature generation protocol. It is shown that the scheme does not ensure strong unforgeability, i.e., it allows to create the forgeries for “old” messages that were legitimately signed. An analysis of the weak unforgeability property (the adversary’s task is to create a forgery for a new message) is also conducted. Using the reduction method, we obtain a security bound on the weak unforgeability property in the algebraic group model and random oracle model. This estimation identifies the base problems whose complexity underpins the scheme security.