Efficient Identity Based Multi-Signcryption Scheme with Public Verifiability
G. Swapna, P. Vasudeva Reddy · Journal of Discrete Mathematical Sciences and Cryptography · 2014
Signcryption is a cryptographic primitive that provides the functionalities of digital signature and public key encryption simultaneously, at a lower computational costs and communication overheads than the traditional signature-then-encryption approach. In some applications, it is often required that multiple senders have to send a message in a secure and authenticated way. If signcryptions are performed individually by the group of senders, the cost involved in unsigncryption is high. So that it is not an efficient way to signcrypt the message separately. An efficient alternative method is multi-signcryption. In this paper, we propose an efficient identity based multi-signcryption scheme with public verifiability. This scheme provides the functionalities of both multi signatures and secure encryption for multiple senders; and these schemes enables to perform unsigncryption with the cost equal to a single unsigncryption irrespective of the number of senders. We discuss the security requirements such as confidentiality and unforgeability of the proposed scheme with the assumptions that the CBDH and CDH problems are intractable. Finally, we compare our scheme with the related schemes in terms of computational point of view.