Analysis and improvement of authenticatable ring signcryption scheme

Abstract

Abstract. Ring signcryption is an anonymous signcryption which allows a user to anonymously signcrypt a message on behalf of a set of users including himself. In an ordinary ring signcryption scheme, even if a user of the ring generates a signcryption, he also cannot prove that the signcryption was produced by himself. In 2008, Zhang, Yang, Zhu, and Zhang solve the problem by introducing an identity-based authenticatable ring signcryption scheme (denoted as the ZYZZ scheme). In the ZYZZ scheme, the actual signcrypter can prove that the ciphertext is generated by himself, and the others cannot authenticate it. However, in this paper, we show that the ZYZZ scheme is not secure against chosen plaintext attacks. Furthermore, we propose an improved scheme that remedies the weakness of the ZYZZ scheme. The improved scheme has shorter ciphertext size than the ZYZZ scheme. We then prove that the improved scheme satisfies confidentiality, unforgeability, anonymity and authenticatability.

ID-based key-insulated signcryption with equality test in cloud computing

“…The deployment of signcryption ensures the attainment of less computational cost. In view of this, several schemes on signcryption have been constructed [20,22] and a combination of digital signature and signcryption [21,23] cryptosystems with its variants in proxy-signcryption [24][25][26], anonymous signcryption [11,27] and ring signcryption [10,28].…”

A Survey of Identity-based Signcryption

“…Identity-based ring signcryption is very useful to protect privacy and authenticity of a collection of users who are connected through an ad hoc network. Subsequently, some identity-based ring signcryption schemes were proposed [39][40][41][42][43][44].…”

“…Selvi et al [46] showed that the schemes mentioned in Refs [41,42] are not secure against adaptive chosen ciphertext attacks and the schemes mentioned in Refs [43,44] are not secure against chosen plaintext attacks. Selvi et al also proposed a new scheme and proved the security of the new scheme in the random oracle model.…”

Post-quantum Secure Hybrid Ring Signcryption Scheme from Lattice Assumption

“…Ring signcryption scheme is proposed by combining the conceptions of ring signature and signcryption together which provides not only confidentiality and authenticity but also the anonymity of the sender. However, the identity authenticity of the actual signer may be important in practical applications [7][8][9]. To achieve identity authenticity in a different way, we make a natural extension from signcryption tag-KEM [6] to ring signcryption tag-KEM.…”