The invention discloses an anonymous participant identity-based
signcryption method for multiple receivers, solving the technical problem that the safety of the current
signcryption method for multiple receivers is poor. The technical scheme comprises the steps of (1) sender
signcryption: a sender IDs selects n
authorization receivers ID1, ID2, ellipsis, IDn, builds an
authorization receiver identity information
list L={ID1, ID2, ellipsis, IDn}, constructs a signcryption
ciphertext C=<Y, X, U, sigma, W, T, J>, and broadcasts the signcryption
ciphertext C so as to complete signcryption operation; and (2)
receiver decryption: a
receiver IDi calculates h'=H4 (sigma, X, U, T, J) according to elements in the signcryption
ciphertext C firstly, then judges whether an equation e (W, P)=e (X+h'Y, Ppub) is workable,
decodes a message ciphertext sigma by using a symmetrical decipherment
algorithm Dk() to obtain a cleartext M=DK(sigma), and completes the decryption process. The sender is anonymous through constructing a pseudo public key, meanwhile Lagrange's interpolation is adopted for fusing identity information of all the
authorization receivers to realize that the identities of the authorization receivers are anonymous for non-authorization receivers, and the safety of the signcryption method for multiple receivers is improved.