METHOD AND DEVICE FOR CERTIFICATELESS PARTIALLY BLIND SIGNATURE

摘要

The present invention belongs to the field of information security technology. A method for certificateless partially blind signature (CL-PBS), comprising: establishing a public system parameter params={G₁, G₂, P, e, g, H₀, H₁, H₂, P_pub}; a signer extracting (S_ID) as a private key and extracting (P) as a public key; the signer randomly selecting γ∈Z*_q, and calculating z=H₀(c) and R=rP, and transmitting R to a signature requester; having received R, the signature requester randomly selecting blinding factors α and β∈Z*_q, and calculating z=H₀(c), R'=αR, (y), h'=H₂(m, z, y), h=α^-1(β-h'), and transmitting h to the signer; having received h, the signer calculating (S), and transmitting S to the signature requester; the signature requester performing an unblinding operation, calculating S'=αS, and obtaining σ= (y, h', S') as a signature for a message m and a negotiation message c; and a verifier performing signature verification. The method effectively solves the security problem caused by the falsification of negotiation public information during the CL-PBS.