Digital signature/multisignature schemes giving public key verification and message recovery simultaneously

The authors propose new digital signature/multisignature schemes using ID-b ased self-certified public keys. The proposed schemes simultaneously accomp lish the tasks of public key verification, signature/multisignature verific ation, and message recovery in a logically single step. Hence, they gain mu ch efficiency in saving both the communicational cost and the computational effort as compared to previous works where these three tasks are performed independently and subsequently. As to the proposed multisignature scheme, both the size and the verification time of a multisignature are almost equi valent to that of any individual signature that contributes to the construc tion of the multisignature.