Multi-proxy Signature Scheme Research Articles

Cryptanalytic Performance Appraisal of Improved CCH2 Proxy Multisignature Scheme

Many of the signature schemes are proposed in which thetout ofnthreshold schemes are deployed, but they still lack the property of security. In this paper, we have discussed implementation of improved CCH1 and improved CCH2 proxy multisignature scheme based on elliptic curve cryptosystem. We have represented time complexity, space complexity, and computational overhead of improved CCH1 and CCH2 proxy multisignature schemes. We have presented cryptanalysis of improved CCH2 proxy multisignature scheme and showed that improved CCH2 scheme suffered from various attacks, that is, forgery attack and framing attack.

Cryptanalysis and Improvement of a Certificateless Multi-proxy Signature Scheme

Certificateless cryptography is a new type of public key cryptography, which removes the certificate management problem in traditional public key cryptography and the key escrow problem in identity-based public key cryptography. Multi-proxy signature is an extension of proxy signature, which allows an original signer authorizing a group of proxy signers and only the cooperation of all proxy signers in the group can create valid proxy signatures on behalf of the original signer. Recently, Jin and Wen combined certificateless cryptography with multi-proxy signature, and proposed a model as well as a concrete scheme of certificateless multi-proxy signature. They claimed that their scheme is provably secure in their security model. Unfortunately, in this paper by giving two attacks, we will show that their certificateless multi-proxy signature scheme can be broken. The first attack indicates their security model is flawed and the second attack indicates their certificateless multi-proxy signature scheme is insecure. Possible improvements are also suggested to prevent these attacks.

Independent Verification of Proxy Multi-Signature without Random Oracle

Privacy has become one of the most important human rights of the modern age. In a proxy multi-signature scheme, the verifier need get all the original signers’ public keys together to verify its validity. However, the relationships between the proxy signer and the original signers would be leaked in the verification process. In this paper, we propose a secure proxy multi-signature scheme in standard model with the property of independent verification. In the scheme, the verifier can verify the signature using the public keys of the special original signers, rather than collecting all the original signers’ public keys.

An Anonymous but Accountable Proxy Multi-signature Scheme

in a proxy multi-signature, the proxy signer can sign a message on behalf of more than one original signer. However, in some cases, the proxy or the original signers do not want to leak the proxy signer's identity. In addition, when something is wrong with the signed message , the identity of the proxy signer has to be revealed. So the problem of anonymous but accountable ha s been proposed. Using the technology of pseudonym and secret sharing, in this paper, a simple method was proposed to reach the target of anonymous but accountable. In the scheme, the identity of the proxy signer was anonymous, but when t or more original signers want to reveal the proxy signer's identity, the proxy signer’s identity would be revealed and be demonstrated.

Quantum Proxy Multi-Signature Scheme Using Genuinely Entangled Six Qubits State

A quantum proxy multi-signature scheme is presented based on controlled teleportation. Genuinely entangled six qubits quantum state functions as quantum channel. The scheme uses the physical characteristics of quantum mechanics to implement delegation, signature and verification. Quantum key distribution and one-time pad are adopted in our scheme, which could guarantee not only the unconditional security of the scheme but also the anonymity of the messages owner.

Efficient ID-based proxy multi-signature scheme secure in random oracle

Proxy signature schemes enable an entity to delegate its signing rights to any other party, called proxy signer. As a variant of proxy signature primitive, proxymultisignature allows a group of original signers to delegate their signing capabilities to a single proxy signer in such a way that the proxy signer can sign a message on behalf of the group of original signers. We propose a concrete ID-based proxy multi-signature scheme from bilinear pairings. The proposed scheme is existential unforgeable against adaptively chosen message and given ID-attack in random oracle model under the computational Diffie-Hellman (CDH) assumption. The fascinating property of new scheme is that the size of a proxy multi-signature is independent of the number of original signers. Furthermore the proposed scheme is simple and computationally more efficient than other ID-based proxy multisignature schemes.

Proxy Multi-Signature Scheme in the Standard Model

Design of proxy multi-signature scheme that is efficient and provably secure in the standard model is suitable for applications. In this paper, we present a formal security model for proxy multi-signature schemes. We also firstly propose a concrete proxy multi-signature scheme based on Waters signature scheme in the standard model. The proposed scheme is proved secure under the computational Diffie-Hellman assumption.

(t,k,n) Multi-Blind Proxy Signature Scheme on Elliptic Curve

On the elliptic curve cryptosystem proposed a new multi-proxy signature scheme - (t, k, n) threshold blind proxy signature scheme.In new program blind proxy signature and (t,k,n) threshold secret sharing scheme will be combined, and will not over-concentration of the rights of the blind proxy signer .Computation of the program is small, security is high, the achieve efficiency and the utility is better .can prevent a malicious user's forgery attack and have the security properties of proxy signature.

An ID-Based Proxy Multi-Signature Scheme

Proxy multi-signature is an extension of the basic proxy signature primitive, and permits two or more entities to delegate their signing capabilities to the same other entity. Combining proxy multi-signature with identity based cryptography, in this paper, We construct a concrete identity based proxy multi-signature scheme by using bilinear pairings. Analysis shows that the scheme is capable of resisting forgery attack and can satisfy all the required security properties of a proxy signature. Furthermore, the new scheme is very simple and efficient computationally. It has the property that the size of a proxy multi-signature is independent of the number of the original signers.

Attacks on Self-Certified Multi-Proxy Signature Schemes with Message Recovery

Signature schemes with message recovery based on self-certified public keys can reduce the amount of communications and computations, since the signature verification, the public key authentication and the message recovery are simultaneously carried out in a single logical step. Integrating self-certified public-key systems and the message recovery signature schemes, in 2009, Wu et al. proposed two multi-proxy signatures based on the discrete logarithms over a finite field and the elliptic curve discrete logarithms. The proxy warrant revision attacks are proposed, and it will show that Wu et al.’s schemes can not resist the proxy warrant revision attacks by either the proxy group or the original signer.

An Improved Proxy Multi-Signature, Multi-Proxy Signature and Multi-Proxy Multi-Signature Scheme

Zhou’s proxy multi-signature scheme was a safe and effective scheme, but this scheme was not safety enough. In this work, security analysis was given to the scheme and results showed that the scheme was very easy aggressed by the forgery attack. The paper proposed that any attacker can sign some certain unauthorized messages after the attacker knows a valid signature, and any original signer ally with his proxy signer can forge any unauthorized messages. Then, the paper gave two kinds of inside attacks and outside attacks to the scheme correspondingly. Finally this paper proposed a new improved proxy multi-signature, multi-proxy signature and multi-proxy multi-signature schemes which based on the difficulty of the discrete logarithm problem (DLP). With verifying all the signers’ public keys, the improved schemes can resist lots of outsider attack and insider attack. The validity of the new scheme can be verified, and they are secure signature schemes.

Improvement of a Forward-Secure Multi-Proxy Signature Scheme

This paper shows some insecurities in Xu’s forward secure multi-proxy signature scheme. There are two kinds of attacks on this scheme: (1) anyone can forge some certain messages which to be sign and cannot detect by the signature verifier. (2) This scheme can’t resist the dishonest signer forgery attack by forging its own public key. After that, the paper proposed two new forward-secure multi-proxy signature schemes based on discrete logarithm problem and quadratic residues. With verifying all the signers’ public keys, the improved schemes can resist lots of outsider attack and insider attack as above mentioned. The validity of the new scheme can be verified, and they are secure multi-signature schemes.

On the security of an identity based multi-proxy signature scheme

In a multi-proxy signature scheme, an original signer could authorize a proxy group as his proxy agent. Then only the cooperation of all the signers in the proxy group can generate the proxy signatures on behalf of the original signer. Recently, Cao and Cao gave the first formal definition and security model of an identity-based multi-proxy signature scheme, then proposed an identity-based multi-proxy signature scheme from bilinear pairings and proved its security in their security model. Although they proved that their scheme is secure under this model, we disprove their claim and show that their scheme is not secure. We also present a simple fix to prevent this attack.

A New ID-based Designated Verifier Proxy Multi-Signature Scheme

Proxy multi-signature allows a proxy signer to generate signatures on behalf of a group of original signers. In a designated verifier signature scheme, the signature only can be verified by a designated person. In this paper, we give the model of ID-based designated verifier proxy multi-signature and present a new ID-based designated verifier proxy multi- signature scheme. Its security is based on the computational Diffie-Hellman (CDH) problem and it is highly efficient.

Certificateless multi-proxy signature

Multi-proxy signature is a scheme that an original signer authorizes a proxy group as his proxy agent and later only the cooperation of all proxy signers in the proxy group could sign messages on behalf of the original signer. To our best knowledge, most of the existing multi-proxy signature schemes are proposed in public key infrastructure or identity-based setting. However, due to avoiding the inherent escrow problem of identity-based cryptography and yet not requiring certificates to guarantee the authenticity of public keys, certificateless public key cryptography has become an attractive paradigm on which many cryptographical primitives are based. In this paper, a generic construction and a formal security model of certificateless multi-proxy signature (CLMPS) are firstly defined. A concrete CLMPS scheme is also proposed, which is proven to be existentially unforgeable against adaptively chosen warrant attacks and chosen message and identity attacks in the random oracle model under the computational Diffie–Hellman assumption.

Provably secure multi-proxy signature scheme with revocation in the standard model

Multi-proxy signature schemes are very useful tools when an original signer needs to delegate his signing capability to a group of proxy signers, and have been suggested in numerous applications. The proxy revocation problem is an essential issue of the proxy signature schemes, however, it is seldom considered in the multi-proxy signature schemes. In this paper, we give a formal definition and security model of the multi-proxy signature schemes with proxy revocation, and propose a multi-proxy signature scheme with proxy revocation. Our scheme can perform the immediate revocation by using a security mediator (SEM), who examines whether each proxy signer signs according to a warrant or its identity exists in a revocation list, and then decides if it issues a proxy token for each proxy signer. The proposed scheme is proven existentially unforgeable against chosen message/warrant attacks based on the computational Diffie–Hellman intractability assumption in the standard model. Furthermore, the size of a multi-proxy signature is constant and independent of the number of the proxy signers.

Improvement of a proxy multi-signature scheme without random oracles

A proxy multi-signature scheme permits two or more original singers to delegate their signing powers to the same proxy signer. Recently, Liu et al. proposed the first proxy multi-signature that be proven secure in the standard model [Liu et al. (2008) [20]], which can be viewed as a two-level hierarchical signature due to Waters. However, because of the direct employment of Waters’ signature, their scheme needs a relatively large number of public parameters and is not tightly reduced to the security assumption. In this paper, inspired by Boneh, Boyen’s technique and Waters’ technique, we propose a new proxy multi-signature scheme without random oracles, whose unforgeability can be tightly reduced to the CDH assumption in bilinear groups. The new scheme can be regarded as an improvement to overcome the weaknesses of Liu et al.’s scheme. Compared with Liu et al.’s scheme, the improvement has three merits, tighter security reduction, shorter system parameters and higher efficiency.

On the security of an identity-based proxy multi-signature scheme

In 2000, Yi et al. proposed two proxy multi-signature schemes which enable two or more original signers to delegate their signing power to a proxy signer. Combining proxy multi-signature with identity-based cryptography, Wang et al. proposed an identity-based proxy multi-signature scheme in 2007. Their scheme is claimed to be secure in the random oracle model. However, in this study, the author shows that Wang et al.'s scheme is vulnerable to a forgery attack described in this study.

A Proxy Multi-Signature Scheme with Anonymous Vetoable Delegation

Frequently a group of people jointly decide and authorize a specific person as a representative in some business/poitical occasions, e.g., the board of a company authorizes the chief executive officer to close a multi-billion acquisition deal. In this paper, an integrated proxy multi-signature scheme that allows anonymously vetoable delegation is proposed. This protocol integrates mechanisms of private veto, distributed proxy key generation, secure transmission of proxy key, and existentially unforgeable proxy multi-signature scheme. First, a provably secure Guillou-Quisquater proxy signature scheme is presented, then the “zero-sharing” protocol is extended over a composite modulus multiplicative group, and finally the above two are combined to realize the GQ proxy multi-signature with anonymously vetoable delegation. As a proxy signature scheme, this protocol protects both the original signers and the proxy signer. The modular design allows simplified implementation with less communication overheads and better computation performance than a general secure multi-party protocol. Keywords— GQ proxy signature, proxy multi-signature, zerosharing protocol, secure multi-party protocol, private veto protocol

Self-certified multi-proxy signature schemes with message recovery

Multi-proxy signature schemes allow the original signer to delegate his/her signing power to n proxy signers such that all proxy signers must corporately generate a valid proxy signature on behalf of the original signer. We first propose a multi-proxy signature scheme based on discrete logarithms and then adapt it to the elliptic curve cryptosystem. With the integration of self-certified public-key systems and the message recovery signature schemes, our proposed schemes have the following advantages: (1) They do not require the signing message to be transmitted, since the verifier can recover it from the signature; (2) The authentication of the public keys, verification of the signature, and recovery of the message can be simultaneously carried out in a single logical step; (3) No certificate is needed for validating the public keys. Further, the elliptic curve variant with short key lengths especially suits the cryptographic applications with limited computing power and storage space, e.g., smart cards. As compared with the previous work that was implemented with the certificate-based public-key systems, the proposed schemes give better performance in terms of communication bandwidth and computation efforts.