Final answer:
A secure signature scheme is a cryptographic protocol that allows a sender to digitally sign a message and ensure its authenticity and integrity.
Step-by-step explanation:
A secure signature scheme is a cryptographic protocol that allows a sender to digitally sign a message and ensure its authenticity and integrity. It provides a way for the receiver to verify that the message came from the claimed sender and that it has not been modified during transit.
One example of a secure signature scheme is the RSA algorithm. In RSA, a sender uses their private key to create a digital signature for the message, and the receiver uses the sender's public key to verify the signature. If the signature is valid, it provides assurance that the message was not tampered with and came from the specified sender.
Other secure signature schemes include the Digital Signature Algorithm (DSA) and the Elliptic Curve Digital Signature Algorithm (ECDSA).