Abstract: Signcryption is a new cryptographic technology, which simultaneously fulfills both the function of digital signature and public key encryption in a logically single step, and more efficient than the traditional "signature followed by encryption" approach. In this paper we propose a multi-signcryption model based on mlti-signature and signcryption, and various signatures and encryptions can be chosen flexibly in the model. At the same time, the model can be instantiated into the multi-signcryption scheme to a single or a group message and the multi-signcryption scheme which can only be decrypted by multi-receivers.

Key words: multi-signcryption, multisignature, testament protocl