Signcryption as a single cryptographic primitive offers both confidentiality and authentication simultaneously. Generally in signcryption schemes, the message is hidden and thus the validity of the ciphertext can be verified only after unsigncrypting the ciphertext. Thus, a third party will not be able to verify whether the ciphertext is valid or not. Signcryption schemes that allow any user to...

Certificateless public key cryptography combines advantage of traditional public key cryptography and identity-based public key cryptography as it avoids usage of certificates and resolves the key escrow problem. In 2007, Huang et al. classified adversaries against certificateless signatures according to their attack power into normal, strong and super adversaries (ordered by their attack power...

Certificateless cryptography has attracted much attention due to its distinctive features. By eliminating the certification costs in traditional public key cryptography and addressing the private key escrow problem in identity-based cryptography, certificateless cryptography has become a mesmeric paradigm for developing various cryptographic primitives. Digital signatures with short signature l...

In this paper, we analyse the Yang–Wong–Deng signcryption scheme [G. Yang, D.S. Wong, X. Deng, Analysis and improvement of a signcryption scheme with key privacy, in: Information Security Conference—ISC’05, in: Lecture Notes in Comput. Sci., vol. 3650, Springer-Verlag, Berlin, 2005, pp. 218–232] proposed in ISC’05, which is the improvement and enhancement of the security of Libert–Quisquater si...

An Identity-based cryptosystem is a Public Key cryptosystem in which the public keys of the entities are their identities, or strings derived from their identities. Signcryption combines digital signatures and encryption with a cost significantly smaller than that required for signature-then-encryption. This paper proposes an ID-based signcryption scheme based on bilinear pairings on elliptic c...

Signcryption is a new cryptographic primitive that simultaneously fulfills both the functions of signature and encryption. The definition of generalized signcryption is proposed in the paper firstly. Generalized signcryption has a special feature that provides confidentiality or authenticity separately under the condition of specific inputs. So it is more useful than common ones. Based on ECDSA...

Online/Offline signcryption is a cryptographic primitive where the signcryption process is divided into two phases online and offline phase. Most of the computations are carried out offline (where the message and the receiver identity are unavailable). The online phase does not require any heavy computations like pairing, multiplication on elliptic curves and is very efficient. To the best of o...

Certificateless public key schemes without pairing have attracted much attention for its relatively high efficiency. The revocation problem is a very necessary issue in a public key cryptosystem. However, there have been some solutions to the certificateless revocation problem; they still suffer from low efficiency or security weakness. In this paper, we propose a revocable certificateless sign...

Secure aggregate signature schemes have attracted more concern due to their wide application in resource constrained environment. Recently, Horng et al. [S. J. Horng et al., An efficient certificateless aggregate signature with conditional privacy-preserving for vehicular sensor networks, Information Sciences 317 (2015) 48-66] proposed an efficient certificateless aggregate signature with condi...

In this paper the ID-based signcryption scheme of Li, Xin, and Hu is extended to a compartmented scheme. If an organization is partitioned into different compartments, this scheme allows any member of a specific compartment to participate in the unsigncryption; moreover, each member of a compartment has information unique to that individual. This construction is the first (to the authors’ knowl...