An ID-Based Proxy Multi Signature Scheme without Bilinear Pairings

Multi-proxy signature is a variant of proxy signature, which allows that a delegator may delegate his signing rights to many proxy signers. Compared with proxy signature, multi-proxy signature can effectively prevent that some of proxy signers abuse signing rights. In this paper, we propose an efficient multi-proxy signature scheme in the standard model, which is based on the Waters' signature scheme. Compared with other multi-proxy signature schemes in the standard model, the proposed scheme further reduces the amount of computations and communications.

Proxy signatures are efficient alternatives to delegate the signing rights. In a proxy signature scheme, the original signer can delegate its signing rights to any other party, to make signature on its behalf. In a multi-proxy signature scheme, the original signer delegates its signing rights to a group of persons called proxy groups. With the exploit of bilinear pairing over elliptic curves, several ID-based multi-proxy signature schemes have been developed till now [5,9,17]. In this paper, we have proposed an ID-based multi-proxy signature, based on ‘k-plus problem’. The proposed scheme is secure under the INV-CDHP assumption. Moreover, our scheme is computationally more efficient than the schemes [5,9] and assure all the security requirements of a proxy signature, given in [11].KeywordsID-based signaturemulti-proxy signaturebilinear pairing k-plus problemINV-CDHP

A proxy signature scheme enables a signer to transfer its signing rights to any other user, called the proxy signer, to produce a signature on its behalf. Multi-proxy signature is a proxy signature primitive which enables a user to transfer its signing rights to a group of proxy signers in such a way that every member of the authorized group must “participate” to sign a document on behalf of the original signer. We propose an efficient and provably secure identity-based multi-proxy signature scheme from bilinear map based on the hardness of the computational Diffie-Hellman problem. The proposed scheme is proved secure against adaptive chosen message and adaptive chosen-ID attack in random oracle model under the computational Diffie-Hellman assumption. Moreover, we do an efficiency comparison with the existing identity-based multi-proxy signature schemes and show that our scheme is upto 56 % more efficient in computation than the existing schemes.KeywordsIdentity-based cryptographyDigital signatureBilinear mapMulti-proxy signatureProvably secureCDHP

Aggregate signature is widely used in special occasions where the signatures on many different messages generated by many different users need to be compressed into one single signature. This paper presents an efficient certificate-based aggregate signature (CBAS) scheme from bilinear pairing. In the random oracle model, the new scheme is proven existentially unforgeable against adaptive chosen message attacks under the computational Diffie-Hellman assumption. The signature verification of the new scheme only needs constant pairing computations, which improves the efficiency of communication and computation, and it is more suitable for the applications in resource-constrained network environment.

Multi-proxy multi-signature scheme is one of the useful primitives of proxy signature scheme which enables a group of signers to delegate their signing rights to another group of their proxy signers. In literatures, only a few schemes of identity (ID)-based multi-proxy multi-signature (IBMPMS) from bilinear pairings are available but those schemes cannot be considered practical for implementations because either those are insecure or cost inefficient. Whereas due to numerous applications of IBMPMS scheme in distributed systems, grid computing, global distribution networks, etc., construction of an efficient and secure IBMPMS scheme is desired. In this paper, we propose a new construction of IBMPMS scheme from bilinear pairings. We also discuss a security model for IBMPMS schemes and prove that the proposed scheme is existential unforgeable against adaptive chosen-message and adaptive chosen-ID attacks under the computational Diffie–Hellman (CDH) assumption. Moreover, the proposed scheme is more efficient in the view of computation and operation time than the existing schemes. In particular, our scheme is up to 40 % more efficient and faster than the existing similar schemes.

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.

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.

Proxy signature schemes allow a proxy signer to generate a proxy signature on behalf of an original signer. However, since in previous proxy signature schemes a proxy signature is created on behalf of only one original signer, these schemes are referred to as proxy mono-signature schemes. A new type of proxy signature scheme is presented called the proxy multi-signature scheme in which a proxy signer can generate a proxy signature on behalf of two or more original signers.

Certificateless multi-proxy signature

One of the most used authentication methods is based on short secrets like password, where usually the hash of the secrets are stored in a central database. In case of server compromise the secrets are vulnerable to theft. A possible solution to this problem to apply distributed systems. We propose a mutual authentication protocol with key agreement, where identity verification is carried out by multiple servers applying secret sharing technology on server side. The protocol results in a session key which provides the confidentiality of the later messages between the participants. In our solution we also achieve robustness and scalability as well. To show that the proposed protocol is provably secure, we apply the threshold hybrid corruption model. We assume that among the randomly chosen k servers, there is always at least one uncorrupted and the authentication server reveals at most the long-lived keys. We prove that the protocol is secure in the random oracle model, if Message Authentication Code (MAC) is universally unforgeable under an adaptive chosen-message attack, the symmetric encryption scheme is indistinguishable under chosen plaintext attack, moreover Elliptic Curve Computational Diffie-Hellman assumption holds in the elliptic curve group.

In Industrial Internet of Things (IIoT), the certificate-based aggregate signature (CBAS) scheme was used to ensure privacy and security of IIoT, thus, the concrete construction of CBAS scheme without bilinear pairing has proposed, which was employed as an underlying building block to create an efficient data aggregation protocol. In this article, we first point out that the previous CBAS scheme cannot keep its claimed security. Particularly, a malicious KGC can compute a valid forgery signature, because it has the knowledge of the master secret key. After that, we discussed how specific forgery attacks could be made to against the existing CBAS schemes, which demonstrates that the previous related constructions cannot achieve its claimed security. In order to further provide a secure CBAS scheme for IIoT, we suggest a method to improve the CBAS scheme and propose a concrete construction of it. In the random oracle model, based on the hardness of discrete logarithm problem, the security of our new proposal can be proved. Compared with the previous CBAS schemes, our construction has better security, which is efficient with respect to computation and communication.

Proxy signcryption is a novel cryptographic primitive that combines the functionality of a proxy signature with that of a signcryption. However, the security of all the known proxy signcryption schemes were proven in the random oracle, which has received a lot of criticism that the proofs in the random oracle model are not sound with respect to the standard model. Hence, it is an interesting research problem on how to construct a provably secure proxy signcryption scheme in the standard model. In this paper, motivated by Waters' signature scheme, we propose a new construction of proxy signcryption scheme based on bilinear pairing without using random oracles. Then, we use the techniques from provable security to show that the proposed scheme is indistinguishability under adaptive chosen ciphertext attacks secure under the decisional bilinear Diffie–Hellman assumption and existentially unforgeable under the computational Diffie–Hellman assumptions. Compared with the existing schemes with formal security proof, we show that no pairing computation is required in our proxy signcrypt phase with pre‐computations. To the best of our knowledge, our proposed scheme is the first provably secure proxy signcryption scheme in the standard model. Copyright © 2014 John Wiley & Sons, Ltd.

An identity-based multisignature scheme and an identity-based aggregate signature scheme are proposed in this paper. They are both from m-torsion groups on super-singular elliptic curves or hyper-elliptic curves and based on the recently proposed identity-based signature scheme of Cha and Cheon. Due to the sound properties of m-torsion groups and the base scheme, it turns out that our schemes are very simple and efficient. Both schemes are proven to be secure against adaptive chosen message attack in the random oracle model under the normal security notions with the assumption that the Computational Diffie-Hellman problem is hard in the m-torsion groups.

Recently, Boneh and Boyen proposed a new provably secure short signature scheme under the q-strong Diffie-Hellman assumption without random oracles. This scheme is based on bilinear map which is different from Cramer-Shoup signature scheme (which is based on the strong RSA assumption). However, Tan TC[17] showed that Boneh- Boyen scheme is subjected to key substitution attacks in the multi-user setting. In this paper, we propose a new signature scheme. We prove that the proposed scheme is provably secured against existential forgery under adaptive chosen message attack in the standard model and also secure against key substitution attacks.

The trusted delegation of services requires an effective synchronised and verifiable signature scheme to convince the authorisation of involving entities in the delegation processes. The proxy signature scheme enables an original signer to delegate her signing capability to a proxy signer in a secure manner. In this paper, we present a controlled delegation of generating a proxy signature using a control entity (mediator). The mediator controls the delegation capability of the proxy signer for making the signature even before/after the delegation period. We propose a new construction of proxy signature with revocation by using a mediator that controls the delegation capability and authorisation of the proxy signer. The security hardness of the proposed scheme is based on the computational bilinear Diffie-Hellman (CBDH) intractability assumption in the random oracle model. Furthermore, we verify the revocation process of our proposed scheme using model checking.