A Dynamic Threshold Attributes-based Signcryption Scheme

Signcryption combines the functionalities of signature and encryption and costs less than that required by the traditional signature-then-encryption approach. On the basis of Li et al. (2010) attribute-based signature, a new attributes-based signcryption is proposed in this paper, in which not only confidentiality and authentication is provided but also attribute-signcryptor privacy and multi-recipient is achieved. This scheme is provable secure in the random oracle model and it satisfies indistinguishability against adaptive chosen ciphertext attack based on Decisional Bilinear Diffie-Hellman (DBDH) assumption and satisfies existential unforgeability against adaptive chosen message attack based on the standard Computational Diffie-Hellman (CDH) assumption.