A new identity based blind signature scheme and its application

A blind signature enables a user to obtain signatures on any message from an authority who cannot acquire any information on the message being signed. A blind ring signature scheme is designed as a ring signature scheme with the blindness property. The scheme allows any member of a group anonymously sign a message on behalf of the group. Also, the user with the message can blind it before transmitting to the group. At Asiacrypt 2010, Rückert constructed the first blind signature scheme using ideal lattices. Recently, Zhang, Jiang and Zheng, and Alkadri, Bansarkhani and Buchmann proposed two improved blind signature schemes based on the SIS problem and the Ring SIS problem in 2018 and 2020, respectively. At WISA 2019, motivated by these blind signature schemes, Le, Duong and Susilo constructed the first lattice-based blind ring signature scheme provably secure under the hardness assumption of the SIS problem in random oracle model. In this paper, we show that Rückert’s scheme, Alkadri-Bansarkhani-Buchmann scheme and Zhang-Jiang-Zheng scheme, and Le-Duong-Susilo scheme do not achieve blindness, i.e. the signer can link a valid message-signature pair after interacting with various users. We show that the cause of vulnerabilities of the blind schemes is that the blinding factors to hide real messages being signed are exposed by specific algebraic relations in the underlying rings. To hide the blinding factors, we use homomorphic encryption schemes. Finally, we propose a generic construction from a semantically secure homomorphic encryption scheme and a one-more unforgeable blind signature scheme that does not achieve blindness to a new blind signature scheme that achieves blindness as well as one-more unforgeability.

An efficient provably secure identity-based blind signature (IBBS) scheme based on bilinear pairings is proposed. Assuming the intractability of the q-Strong Diffie-Hellman problem, our IBBS is unforgeable under adaptive chosen-message and ID attack. Because of avoiding using the inefficient MapToPoint function, our IBBS can offer advantages in runtime over the schemes available. Based on this ID-based blind signature scheme, we describe the first ID-based threshold blind signature (TBS) and show that it has security properties of unforgeability and robustness.

An efficient provably secure identity-based blind signature (IBBS) scheme based on bilinear pairings is proposed. Assuming the intractability of the q-Strong Diffie-Hellman problem, our IBBS is unforgeable under adaptive chosen-message and ID attack. Because of avoiding using the inefficient MapToPoint function, our IBBS can offer advantages in runtime over the schemes available. Based on this ID-based blind signature scheme, we describe the first ID-based threshold blind signature (TBS) and show that it has security properties of unforgeability and robustness.

Blind signature is an interesting cryptographic primitive which allows user to get signature on his document from signatory authority, without leaking any information. Blind signature is useful in many e-commerce applications where user’s anonymity is the main concern. Since the Zhang et al., was the first to propose the identity based blind signature, many schemes based on bilinear pairing have been proposed. But the computational cost of pairing operation on elliptic curve is around 20 times the point multiplication on an elliptic curve. In order to save the running time, we present a new Identity-Based Blind Signature (ID-BS) scheme whose security is based on elliptic curve discrete logarithm problem (ECDLP). Performance comparison shows that proposed scheme reduces the cost of computation. Security analysis shows that proposed scheme is secure against the adversary and achieves the property of blindness and Non-forgeabillity. At the end; we propose an e-cash payment system based on our ID-based blind signature scheme.

Blind signatures, introduced by Chaum, allow a user to obtain a signature on a message without revealing any thing about the message to the signer. Blind signatures play an important role in plenty of applications such as e-voting, e-cash system where anonymity is of great concern. Identity based(ID-based) public key cryptography can be a good alternative for certificate based public key setting, especially when efficient key management and moderate security are required. In this paper, we propose an ID-based blind signature scheme from bilinear pairings. The proposed scheme is based on the Hess ID- based digital signature scheme. Also we analyze security and efficiency of the proposed scheme.

A blind ring signature scheme is a combination of a ring signature and a blind signature, which allows not only any member of a group of signers to sign on a message on behalf of the group without revealing its identity but also the user who possesses the message to blind it before sending to the group to be signed. Blind ring signature schemes are essential components in e-commercial, e-voting etc. In this paper, we propose the first blind ring signature scheme based on lattices. More precisely, our proposed scheme is proven to be secure in random oracle model under the hardness of the short integer solution (SIS) problem.

Blind signature allows a user to obtain a signature from an authority on any document, in such a way that the authority learns nothing about the message that is being signed. The blindness is an important property which distinguishes the blind signature from other signature schemes. Partially blind signature is an extension of blind signature that allows a signer to sign a partially blinded message that include pre-agreed information in the resulting signatures. Recently, Liao et al. proposed a pairing-based provable blind signature scheme without random oracles, and Hu et al. proposed an efficient ID-based partially blind signature scheme with security proof. But in this paper, we show that the two schemes do not satisfy the blindness and partially blindness, respectively. Liao et al.'s scheme is linkability and in Hu et al.'s scheme, a malicious user can replace pre-agreed common information with a special information

The rapid growing big data enforces many organizations to shift their data and services like digital right management, e-payment, and e-voting systems to the cloud. In such cloud-assisted services, the blind signature scheme could be one of the cryptographic tools, which provides the integrity of data and user anonymity. It allows the user to ask the signer for signing on message without disclosing any information about the content to the signer. Since several blind signature schemes have been proposed, but due to the expensive computation and bandwidth cost, they are impractical for the cloud-assisted as well as Internet-based environment. In this paper, we propose a new provable secure identity-based blind signature scheme with message recovery (IDBS-MR) using the elliptic curve cryptography. The proposed IDBS-MR scheme does not transmit the message with the signature while the message is recovered during verification round; hence it has the least message-signature length. The security analysis shows that the proposed IDBS-MR scheme is secured against existential forgery attack under the adaptive chosen message and ID attacks (EF-ID-CMA) under the assumption of solving the ECDL problem, and random oracle model (ROM) and achieves blindness property. The performance analysis shows that our scheme is efficient as compared to related existing schemes.

Restrictive blind signatures allow a recipient to receive a blind signature on a message unknown to the signer but the choice of the message is restricted and must conform to certain rules. Partially blind signatures allow a signer to explicitly include necessary information (expiration date, collateral conditions, or whatever) in the resulting signatures under some agreement with the receiver. Restrictive partially blind signatures incorporate the advantages of these two blind signatures. In this paper we first propose a new restrictive partially blind signature scheme from bilinear pairings. Since the proposed scheme does not use Chaum-Pedersen's knowledge proof protocol, it is much more efficient than the original restrictive partially blind signature scheme. We then present a formal proof of security in the random oracle model. Moreover, we use the proposed signature scheme to build an untraceable off-line electronic cash system followed Brand's construction.

Electronic voting is an alternative mechanism of ballot based voting which empowers voters to cast their secret and secure vote electronically over a public channel. Many onward-thinking countries are adopting the electronic voting system to upgrade their election process. E-voting system is more complicated to construct. Thus it expects more security as compared to the postal voting system. The objective of the paper is twofold. Firstly, we proposed an efficient blind signature scheme using the identity-based cryptosystem in the random oracle model. The proposed scheme uses the combination of Boldyreva’s blind signature scheme and Choon-Cheon’s Identity-based signature. Additionally, we reduce its security to the Gap Diffie-Hellman Complexity (GDH). Under the adaptive chosen message and ID attacks it is secure against existential forgery attack. We show our proposed system performed better as compared to existing systems. Secondly, we construct an E-voting system based on our ID-based blind signature and Boneh’s short signature scheme (EVS-ID-BS) that fulfills the E-voting security requirements. To the best of our knowledge, EVS-ID-BS is the first practical implementation of E-voting system based on ID-BS Scheme which is constructed in the random oracle model. Proposed EVS-ID-BS scheme provides batch verifiability for a significantly large number of voters, needs less bandwidth cost and require less interaction with election authority.

Universal forgery attacks and selected forgery attacks on both weak and strong blind signature schemes based on Elgamal signature equation proposed by Wang et al. are developed. Without using any secret key, anyone can forge a valid signature through selecting some random parameters. The possibility of forging the blind schemes is analyzed and moreover, an improved weak blind signature scheme and an improved strong blind signature scheme are designed. Also, the securities of the improved blind signatures are analyzed.

In this paper, we propose a practical ID-based (partially)blind signature scheme. Our scheme combines the already existing notions of blind signatures and identity-based cryptography.The signatures are shown secure in the random oracle model. We show how to use our ID-based PBSs to construct an electronic cash (e-cash) system in which multiple banks can securely distribute untraceable e-cash.

Recently, the first ID-based restrictive partially blind signature scheme from bilinear pairing is proposed by Chen et al., which extends the concept of blind signature and possesses the excellent features of partially blind signature, restrictive blind signature and ID-based cryptosystem simultaneously. However, its computational cost is rather high. In order to improve its efficiency, Hu et al. presented another efficient scheme which requires less computing cost. Unfortunately, we find that an adversary can change the predetermined common information, which may include the expiry date and the face value of the e-cash in electronic cash system, without being discovered by the signer. So Hu et al.psilas scheme has security flaw when it is used in electronic cash system. In this paper, we present an improved ID-based restrictive partially blind signature scheme from bilinear pairing which overcomes the security weakness of Hu et al.psilas scheme. We analyze the security of our scheme in the random oracle model and compared the efficiency of our scheme with previous schemes.

Blind signature offer the protection for sender's privacy and become an important primitive for electronic commerce. In this paper, we present a technique of matrix-vector-blinding for lattice-based blind signature. Building on this result, we propose two hierarchical ID-based blind signature schemes from with and without random oracle, which are secure against quantum attacks. We apply the latest technique of lattice basis delegation in fixed dimension from ABB10's[1] scheme to our constructions which contribute to shorter public key and signature. Both of our blind signature schemes are proven to hold the properties of perfect blindness and one-more unforgeableability. Our hierarchical ID-based blind signature schemes are communicationally efficient and needs only one round data exchanges between the signer and the user, and with a shorter public key and signature in comparison with similar schemes[2, 3]. We prove that our scheme is secure assuming that the short integer solution (SIS) problem is hard.

Liao et al. proposed first blind signature schemes without random oracles from pairings and provided security proofs in CIS'05. However, we show that their blind scheme is neither blind, nor unforgeable, anyone not to query the signing oracle can forge signature of any message.