With the wide application of 5G network, much research has been carried out in recent years toward the 5G network slicing technology in order to save 5G network resources and satisfy the service requirements of different users. Different public key cryptosystems may be deployed in different 5G network slicings. Therefore, heterogeneous signcryption is required to achieve secure communications between different 5G network slices. The existing scheme is a one-to-one communication between 5G network slicings. To obtain one-to-many and many-to-one secure communications, two new privacy-preserving heterogeneous signcryption schemes have been proposed in this article based on 5G network slicings, which can accomplish mutual communications between the public key infrastructure (PKI) and the certificateless public-key cryptography. In this work, we present PKI$\to $CLC completely anonymous multireceiver signcryption (PMRCHS) and CLC$\to $PKI heterogeneous aggregate signcryption (CPHAS) schemes based on the 5G Internet of Things (IoT) slicing and the 5G Internet of Vehicle (IoV) slicing. Under the random oracle model (ROM), the proposed schemes have proved to satisfy confidentiality and unforgeability under the computational Diffie–Hellman problem and discrete logarithm problem (DLP). Furthermore, we make comparisons of the proposed work with the existing works in terms of computational cost, communication cost, anonymity, and communication direction. The results show that the proposed schemes are more secure and effective.

In this paper, we present a new efficient authenticated key agreement protocol. Compared with other cross-domain protocols which are all in the same cryptosystem, our protocol is innovatively designed to shift between the Public Key Infrastructure (PKI) and the Identity-based Cryptosystem (IBC). This protocol combined with heterogeneous signcryption method is proved to satisfy confidentiality and unforgeability on the basis of the assumptions of Computational Diffie-Hellman problem (CDHP) and Bilinear Diffie-Hellman problem (BDHP) in the authentication phases, and it simultaneously guarantees the ciphertext anonymity. In addition, it can efficiently resist kinds of active attacks such as known-session key attack, key forge attack, and known-temporary secret key attack. Compared with other two-party authenticated key agreement protocols, the newly proposed key agreement protocol has better security, practicability and efficiency.

Abstract In recent years, secure communication and privacy‐preserving are gaining popularity because of the advent of wireless network. Certificateless cryptography (CLC) and identity‐based cryptography (IBC) have already been widely applied in the area of wireless network. Hence, to achieve secure communication from CLC to IBC, we present a heterogeneous signcryption scheme that enables a sender in the CLC to transmit a message to multi‐receiver in the IBC. Our scheme has no restrictions on the system parameters and master keys; private key generator and key generating center generate their own system parameters and master key for the IBC users and the CLC user, separately. Considering privacy‐preserving in heterogeneous communication, we show that our scheme can realize the anonymity of all receivers. Compared with other schemes, our scheme has more advantages, such as public verification and decryption fairness, which are attractive for wireless network applications. Moreover, our scheme has the indistinguishability against adaptive chosen ciphertext attacks, the existential unforgeability against adaptive chosen messages attacks, and anonymous indistinguishability of encryptions under selective‐ID, chosen ciphertext attack in the random oracle model. Copyright © 2016 John Wiley & Sons, Ltd.