Proxy Signature Scheme with Effective Revocation Using Bilinear Pairings

We present a proxy signature scheme using bilinear pairings that provides effective proxy revocation. The scheme uses a binding-blinding technique to avoid secure channel requirements in the key issuance stage. With this technique, the signer receives a partial private key from a trusted authority and unblinds it to get his private key, in turn, overcomes the key escrow problem which is a constraint in most of the pairing-based proxy signature schemes. The scheme fulfills the necessary security requirements of proxy signature and resists other possible threats

Certificateless Signature Scheme Based on Rabin Algorithm and Discrete Logarithm

Certificateless signature can effectively immue the key escrow problem in the identity-based signature scheme. But the security of the most certificateless signatures usually depends on only one mathematical hard problem, which makes the signature vulnerable when the underlying hard problem has been broken. In order to strengthen the security, in this paper, a certificateless signature whose security depends on two mathematical hard problems, discrete logarithm and factoring problems, is proposed. Then, the proposed certificateless signature can be proved secure in the random oracle, and only both of the two mathematical hard problems are solved, can the proposed signature be broken. As a consequence, the proposed certificateless signature is more secure than the previous signatures. On the other hand, with the pre-computation of the exponential modular computation, it will save more time in the signature signing phase. And compared with the other schemes of this kind, the proposed scheme is more efficient

Scalable Storage Scheme from Forward Key Rotation

Kallahalla et al. presented a RSA-based Forward Key Rotation mechanism in secure storage scheme PLUTUS to ensure that the key used for encrypting updated files is related to the keys for all files in the file group. The encryption scheme based on Forward Key Rotation is such a scheme that only the authorized person is allowed access to the designated files and the previous versions. In this paper, we present a Forward Key Rotation storage scheme based on discrete logarithm and prove its security under random oracle model. Moreover, we propose another improved Forward Key storage scheme from pairing on elliptic curves. Compared to the scheme presented by Kallahalla et al., our scheme uses relatively short keys to provide equivalent security. In addition, the re-generated keys can be verified to ensure that the keys are valid in the improved scheme

A performance improved certificateless key agreement scheme over elliptic curve based algebraic groups

Due to the importance of key in providing secure communication, various Key Agreement protocols have been proposed in the recent years. The latest generation of Public Key Cryptosystems (PKC) called Certificateless PKC played an important role in the transformation of Key Agreement protocols. In this scientific area, several Key Agreement protocols have been proposed based on Bilinear Pairings. However, pairing operation is known as an expensive cryptographic function. Hence, utilization of pairing operation in the mentioned works made them complex from overall computational cost perspective. In order to decrease the computational cost of Key Agreement protocols, several Certificateless Key Agreement protocols have been proposed by the use of operations over Elliptic Curve based Algebraic Groups instead of using Bilinear Pairings. In this paper, we propose a Pairing-free Certificateless two-party Key Agreement protocol. Our results indicate that our secure protocol is significantly more lightweight than existing related works

Attribute Based Pseudonyms : Anonymous and Linkable Scoped Credentials

Attribute-based credentials (ABCs) provide an efficient way to transfer custody of personal and private data to the final user, while minimizing the risk of sensitive data revelation and thus granting anonymity. Nevertheless, this method cannot detect whether one attribute has been used more than once without compromising anonymity when the emitter and consumer collude with one another. The protocol proposed in this article deals with this issue by using a modification of ZSS pairing-based short signatures over elliptic curves and Verheul's self-blinded credentials scheme. Each user can generate an identifier (pseudonym) that is unique and verifiable by everyone in a given scope, without compromising anonymity. However, the identifier cannot be reused in the same scope, since such reuse would be detected

Secure and authenticated key agreement protocol with minimal complexity of operations in the context of identity-based cryptosystems

Recently, a large variety of Identity-Based Key Agreement protocols have tried to eliminate the use of Bilinear Pairings in order to decrease complexity of computations through performing group operations over Elliptic Curves. In this paper we propose a novel pairing-free Key Agreement protocol over elliptic curve based algebraic groups. The results show that our proposed protocol is significantly less complex than related works from complexity of computation perspective

Anonymous signature scheme

In order to hide the identity of a signer, an anonymous signaure scheme is presented in this paper. In this scheme, a signer located in a specified group produces a signautre on behalf of the group. The recipient can verify whether the signature is valid and comes from the specified group, while tracing the signature to its source is impossible. The proposed anonymous signature is similarly to ring signature in some respects, for example, there is no manager, and no revocation mechanism against signer\u27s anonymity. The most different between these two kinds of signatures is that the group in ring signature is adaptively constructed by the signer, while the group in our scheme is fixed

Cloud Based Data Protection in Anonymously Controlled SDN

Nowadays, Software Defined Network (SDN) develops rapidly for its novel structure which separates the control plane and the data plane of network devices. Many researchers devoted themselves to the study of such a special network. However, some limitations restrict the development of SDN. On the one hand, the single controller in the conventional model bears all threats, and the corruption of it will result in network paralysis. On the other hand, the data will be increasing more in SDN switches in the data plane, while the storage space of these switches is limited. In order to solve the mentioned issues, we propose two corresponding protocols in this paper. Specifically, one is an anonymous protocol in the control plane, and the other is a verifiable outsourcing protocol in the data plane. The evaluation indicates that our protocol is correct, secure, and efficient