Computer Security and Cryptography

17.4 THE DESIDERATA OF A DIGITAL SIGNATURE

The requirements of a digital signature system include:

• The signature SIG should be functionally dependent on every component of the message;
• The signature SIG should incorporates some element of time dependence;
• Only the originator should have computationally feasible means to construct a valid signature SIG for a message; and
• Any authorized recipient should have computationally feasible means to verify the validity of a signature S1G for a message.