The invention discloses a
certificate-less multi-message multi-
receiver signcryption method capable of updating a key, used for solving the technical problem that the existing
certificate-less multi-message multi-
receiver signcryption method is complex. The technical scheme is as follows: a user performs registration to generate a public key and a private key himself at first; when needing to perform key updating, the user re-selects a random number, generates the new
verification share and key updating
verification parameters, and then, sends the new
verification share and key updating verification parameters to a
key generation centre KGC through a public channel; after receiving the new verification share and key updating verification parameters, the KGC verifies whether the two satisfya verification equation or not; if so, the original verification share is replaced by the new verification share; otherwise, updating fails; when the KGC updates the public key, the user calculates and updates the private key himself; in a
signcryption process, the identity information and the
plaintext of a sender are encrypted together; a signature parameter is generated by utilization of the private key of the sender; and, after the identity information of the sender is obtained by decryption, corresponding public key verification signature parameters are obtained. The method is simple andpractical.