Forgery Attacks on an ID-Based Partially Blind Signature Scheme

Information Security and Privacy, 2005

A blind signature scheme is a protocol for obtaining a digital signature from a signer, but the signer can neither learn the messages he/she sign nor the signatures the recipients obtain afterwards. Partially blind signature is a variant such that part of the message contains pre-agreed information (agreed by the signer and the signature requester) in unblinded form, while threshold blind signature distributes the signing power to a group of signers such that a signature can only be produced by interacting with a predetermined numbers of signers. In this paper, we propose a threshold partially blind signature scheme from bilinear pairings and an ID-based partially blind signature scheme, which are provably secure in the random oracle model. To the best of authors' knowledge, we give the first discussion on these two notions.

2012

Blind signature allows one user to get a signature without giving the signer any information about the actual message or the resulting signature. In this paper, we aim to improve the recently proposed Lin et al.’s Self-certified Partially Blind Signature Scheme[1] in order to withstand the security flaw in their scheme. The security of the improved scheme is enhanced in the blind signing phase of the scheme. The analysis shows that the proposed scheme resolves security problem in Lin et al.’s scheme and also meets the aspects of security features needed by a partial blind signature. KeywordsPartial blind signature; self-certified; bilinear pairing; security.

International Journal of Innovation, Management and Technology, 2014

A directed signature scheme allows a designated verifier to directly verify a signature issued to him, and a third party to check the signature validity with the help of the signer or the designated verifier as well. Directed signatures are applicable where the signed message is sensitive to the signature receiver. Due to its merits, directed signature schemes are suitable for applications such as bill of tax and bill of health. In this paper, we proposed efficient identity based directed signature scheme from bilinear pairings.

IJSRD, 2013

Blind signatures introduced by Chaum, allow a user to obtain a signature on a message without revealing anything 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. 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 we propose an ID based blind signature scheme from bilinear pairings.

Research Journal of Applied Sciences, Engineering and Technology, 2013

Untraceability" is an important property of Proxy blind signature. Zhang proposed some new untraceable blind signatures in order to enhance the security of Cai et al. (2007) and Hu et al. (2007)'s schemes. However, this study shows there are three important conclusions: 1. By reduction, we prove that the cryptanalysis method proposed by Zhang is improper and Cai et al. (2007)'s schemes does satisfy the property of untraceability; 2. On that basis, we pinpoints a new analysis method of untraceability which has effectively proved that Hu et al. (2007)'s scheme doesn't satisfy the property of untraceability. Furthermore, the method can be used as a standard method which could analyze other schemes related with blind signature; 3. Zhang's scheme is unpractical since the cost of the scheme is higher compared with Cai et al. (2007)'s scheme.

2012

Recently, many existing partially blind signature scheme based on a single hard problem such as factoring, discrete logarithm, residuosity or elliptic curve discrete logarithm problems. However sooner or later these systems will become broken and vulnerable, if the factoring or discrete logarithms problems are cracked. This paper proposes a secured partially blind signature scheme based on factoring (FAC) problem and elliptic curve discrete logarithms (ECDL) problem. As the proposed scheme is focused on factoring and ECDLP hard problems, it has a solid structure and will totally leave the intruder bemused because it is very unlikely to solve the two hard problems simultaneously. In order to assess the security level of the proposed scheme a performance analysis has been conducted. Results have proved that the proposed scheme effectively deals with the partial blindness, randomization, unlinkability and unforgeability properties. Apart from this we have also investigated the computat...

Proceedings of the 6th WSEAS International …, 2006

In this paper, we propose a new fair blind signature scheme with message recovery using pairing-based self-certified public key cryptosystems. Preserving the merits inherent in pairing-based cryptosystems, it can possess fewer bits to achieve the higher security level. In addition, our new scheme has the advantage that the authentication of the public key can be accomplished with the verification of the fair blind signature in a logically single step. Furthermore, the fairness of blind signature with message recovery can be actually achieved in our proposed scheme. Based on the proposed security proofs and performance evaluation, we affirm that we not only improve the efficiency of the previously proposed schemes, but also achieve the essential properties of blind signature with provable security.

Blind signature is a variant of digital signature which helps the user to obtain a signature without giving any information about the message to the signer and the signer cannot tell which session of the signing protocol corresponds to which message. Blind signatures may seem to be a myth; it is a practical reality due to its wide applications in real life like e-coin and e-voting. This paper focuses on the study of variants of blind signatures with its eminent real world applications. It also discuses about future research scope of blind signatures.

Journal of Computer Security, 2013

Blind signatures allow users to obtain signatures on messages hidden from the signer; moreover, the signer cannot link the resulting message/signature pair to the signing session. This paper presents blind signature schemes, in which the number of interactions between the user and the signer is minimal and whose blind signatures are short. Our schemes are defined over bilinear groups and are proved secure in the common-reference-string model without random oracles and under standard assumptions: CDH and the decision-linear assumption. (We also give variants over asymmetric groups based on similar assumptions.) The blind signatures are Waters signatures, which consist of 2 group elements. Moreover, we instantiate partially blind signatures, where the message consists of a part hidden from the signer and a commonly known public part, and schemes achieving perfect blindness. We propose new variants of blind signatures, such as signer-friendly partially blind signatures, where the public part can be chosen by the signer without prior agreement, 3-party blind signatures, as well as blind signatures on multiple aggregated messages provided by independent sources. We also extend Waters signatures to non-binary alphabets by proving a new result on the underlying hash function.