Short Certificateless Proxy Signature Scheme with Provable Security

A new formal model of security for proxy signature schemes is presented and a provably secure short proxy signature scheme is proposed from bilinear maps. The proposed proxy signature scheme is based on two short secure signature schemes. Finally, a security proof of the proposed proxy signature scheme is showed by reducing directly the security of the proxy scheme to the security of the two basic signature schemes. The proposed proxy signature scheme has the shortest proxy signatures, the proxy signature generation needs no pairing operation and verification needs just one pairing operation.

Proxy signature has drawn great concerns. However, there still remains a challenge to construct a provably secure and efficient proxy signature scheme. In this paper, we propose an efficient proxy signature scheme based on factoring, and prove that it is secure in the random oracle. Furthermore, we present a new type of proxy signature, called Proxy Signature with Untrustworthy Proxy Signer, and construct a concrete scheme.

Proxy signature is a powerful cryptographic primitive for delegating the signing powers. In this paper, we propose a new construction of novel proxy signature scheme, in which the proxy signing efficiency is highly efficient. Specifically, we describe a new and efficient proxy signature scheme from DL assumption. Our construction makes use a exposure free chameleon hash function in the delegation phase and the proxy signer needs only to find a collision to generate a valid proxy signature, which dramatically reduces the computation cost of the proxy signer. Our analysis demonstrates that the new scheme achieves all the desirable properties that a secure proxy signature scheme should provide.

Identity-based proxy signature (IDBPSE) has attracted many researchers and scholars since it can simplify key management procedure of certificate-based public key setting. Recently, some IDBPSE schemes are constructed in the standard model. However, most of them have very loose security reductions. And they cannot resist the attack from the delegator and have low computational efficiency. In this study, a novel and efficient IDBPSE scheme is constructed, and we also prove its security based on the computational Diffie–Hellman assumption. Compared with other existing IDBPSE schemes, our scheme has two main advantages: tight security reduction and more complete security including resisting the delegator attack. And our scheme has more efficient performance including less computational cost and shorter signature size than most of existing similar IDBPSE schemes. What is more, our scheme does not require secure channels to transfer delegation keys, but other identity-based proxy signature schemes need.

Mobile agents are able to migrate across different execution environments through network. However, proxy signature is a signature that an original signer delegates his signing capability to a proxy signer. If a mobile agent may act as a proxy signer to produce signatures on behalf of the agent owner autonomously on remote hosts, this will increase efficiency of the agent owner. In this work we propose a novel and secure non-designated proxy signature scheme with revocation. This work is different from other related proxy signature scheme in that in addition to providing non-repudiation, the method provides the proxy signer's privacy which be realized by Alias Issuing authority. if need be, the proxy signer's privacy can be revoked. and a prominent character is that Alias Issuing authority is untrusty, even though he colluded with the original signer, they also cannot forge a proxy signature. These features are attractive for proxy signature in agent-based paradigm in which proxy signers are mobile agents that are executed in remote untrustworthy host.

Recently, the notion of the key-insulated public- key system has been suggested to protect the security of users' private keys. A general idea of this system is changing the user's private key along with the time, but the user's public key remains unchanged. In this paper, we propose a new identity (ID)-based key-insulated signature scheme from bilinear pairings. As compared with the recently proposed ID-based key-insulated signature schemes, our proposed scheme has better performance in the batch verifying phase. For security analysis, our scheme is a provably secure key-insulated signature scheme in the random oracle model and under the computational Diffie-Hellman assumption. Meanwhile, to demonstrate the additional advantage of a key-insulated signature, we present a novel application based on the proposed scheme, called full delegation ID-based proxy signature scheme with time restriction. To our best knowledge, no such a proxy signature scheme is proposed until now.

A proxy signature scheme allows one user to delegate his/her signing capability to another user called a proxy signer in such a way that the latter can sign messages on behalf of the the former. After verification the verifier is convinced of the original signer's agreement on the signed message. We have come up with a scheme to control delegation of financial power to a proxy signer. The scheme satisfies the basic requirements of a secure proxy signature scheme. Using our scheme the proxy signer will be able to submit an e-cheque for only the amount he is entitled to by the original signer. Any cheating by the original signer or the proxy signer is identified by the verifier i.e. the bank. We have considered Forgery by the original signer, Impersonating and framing attack to prove the security of our scheme. Any discrete log based signature scheme can be used to sign the messages. Here we use the digital signature algorithm (DSA).

A proxy signature scheme allows an entity to delegate its signing capability to another entity (proxy) in such a way that the proxy can sign messages on behalf of the delegator. Proxy signatures have found numerous practical applications such as distributed systems, mobile agent applications, etc. Recently, Xu, Zhang and Feng proposed the first formal models of identity based proxy signature. Unfortunately, their model does not capture the notion of adaptively chosen message and chosen identity attacker in identity based system. In this paper, we redefine the security models of identity based proxy signature to capture the most stringent attacks against adaptively chosen message and chosen identity attacker. We also propose a new provably secure identity basad proxy signature scheme whose security is based on the hardness of Computational Diffie-Hellman problem in the random oracle model.

Digital signature with proxy delegation, which is a secure ownership enforcement tool, allows an original signer to delegate signature rights to a third party called proxy, so that the proxy can sign messages on behalf of the original signer. In today’s modern society, many applications use this mechanism. Several types of delegations are quite prevalent and the delegation of signing authority is one of them. In a traditional digital signature scheme, signer transmits signature along with message for verification, which leads to additional communication, computation cost and requires extra bandwidth. To resolve these issues, in this paper, we present an efficient ID-based proxy signature scheme with message recovery using bilinear pairings. Because of the message recovery feature, the proxy signer need not send the message to the verifier, so that the proposed scheme reduces the bandwidth requirement and communication cost. Our proposed scheme is proven secure against existential forgery under adaptively chosen message and identity attacks in the random oracle model (ROM) with the assumption that the Computational Diffie-Hellman Problem (CDHP) is intractable. We compare our scheme with related schemes. The efficiency analysis shows that the scheme is computationally efficient. Thus the proposed ID-based proxy signature scheme is secure and efficient both in terms of computation and communication costs than the related existing schemes.

A proxy signature scheme permits an entity to delegate its signing rights to another. Proxy signature scheme has been widely used in numerous applications. This paper proposed a proxy signature scheme based on lattice cryptography which is different from traditional proxy signature schemes. This scheme combines the idea of the traditional proxy signature and the lattice-based signature together. The security of the proposed scheme is based on the Short Integer Solution (SIS) problem, the proposed proxy signature scheme has smaller key size and lower computation cost. We use the Bimodal Gaussian Distribution, Reject Sampling, Hash matrix and other technologies to extend the original digital signature scheme to the proxy signature scheme. In this paper we will give the security proof of the proxy signature scheme. Moreover, since the key construction of the scheme is based on the operation of the ring, so the public and private key size can be greatly shrunk.

Proxy signature schemes based on factoring

Internet of Things (IoT) is made up of various smart devices for the exchange of sensed data through online services. Direct contact with people through smart devices to define parameters for healthcare and send them to a centralized repository. At the time of data exchange, messages need to be secure between a source (sender) and target (receiver) in order to confront human malicious attacks. Various signature-based schemes are presented in the literature to provide secure communication. Smart apps, however, require lightweight activities by maintaining critical security strengths. The key challenge in signature-based methods is more incurred computational expense for signing and checking process involving large numbers. In this article, a new lightweight provably secure partial discrete logarithm (DL) based subtree-based short signature with fuzzy user data sharing for human-centered IoT systems is introduced and it's security analysis is demonstrated on random oracle (RO) model. The presented scheme provides assurance of better security than other standing short-signature schemes. For low-storage, low-computation environments and low-bandwidth communication, the presented new provably secure and lightweight subtree-based short-signature scheme is needed. The results demonstrate the strength of proposed scheme, as opposed to existing works.

In a proxy signature scheme, a user delegates his/her signing capability to another user in such a way that the latter can sign messages on behalf of the former. In this paper, we first propose a provably secure proxy signature scheme, which is based on a two-party Schnorr signature scheme. Then, we extend this basic scheme into designated-verifier proxy signatures (DVPS). More specifically, we get two versions of DVPS: weak DVPS and strong DVPS. In both versions, the validity of a proxy signature can be checked only by the designated verifier. In a weak DVPS scheme, however, the designated verifier can further convert such proxy signatures into public verifiable ones, while a strong DVPS scheme does not have the same property even if the designated verifier’s secret key is revealed willingly or unwillingly. In addition, we briefly discuss some potential applications for DVPS.Keywordsproxy signaturedigital signatureinformation security

Based on the GDH signature (short signature scheme) a probabilistic signature scheme is proposed in this paper with security proof. Then a new threshold proxy signature from bilinear pairings is proposed as well by using the new probabilistic signature scheme and the properties of the Gap Diffie-Hellman (GDH) group (where the Computational Diffie-Hellman problem is hard but the Decisional Diffie-Hellman problem is easy to solve). Our constructions are based on the recently proposed GDH signature scheme of Bonel et al.’s article. Bilinear pairings could be built from Weil pairing or Tate pairing. So most our constructions would be simpler, but still with high security. The proposed threshold proxy signature is the first one which is built from bilinear pairings. At the end of this paper security and performance of the threshold proxy signature scheme is also analyzed.

Delegation of rights is a common practice in the real world. Proxy signature schemes have been invented to delegate signing capability efficiently and transparently. In this paper, we present a new nonrepudiable proxy signature scheme. Nonrepudiation means the signature signers, both original and proxy signers, cannot falsely deny later that he generated a signature. In practice, it is important and, sometimes, necessary to have the ability to know who is the actual signer of a proxy signature for internal auditing purpose or when there is abuse of signing capability. The new nonrepudiable proxy signature scheme also has other desirable properties, such as proxy signature key generation and updating using insecure channels. We also show how to construct threshold proxy signature schemes with an example. Threshold signatures are motivated both by the need that arises in some organizations to have a group of employees agree on a given message (or a document) before signing it, as well as by the need to protect signature keys from the attack of internal and external adversaries. Our approach can also be applied to other ElGamal-like proxy signature schemes.