A valid digital signature, where the prerequisites are satisfied, gives a recipient very strong reason to believe that the message was created by a known sender ( authentication), and that the message was not altered in transit ( integrity). that the encrypted copy, decrypted using the public key, exactly matches the original message.Ī digital signature is a mathematical scheme for verifying the authenticity of digital messages or documents.
He uses Alice's public key to verify the authenticity of the message, i.e. Bob receives both the message and signature.
Alice signs a message-'Hello Bob!'-by appending to the original message a version encrypted with her private key.
