The verification signer must cooperate with the signer to verify whether the signature is completed by asking and answering the protocol. This agreement can prevent the signer from denying his previous signature.

1. Others can't forge the signature of the message, because the private key is only known to the signer, so others can't forge the correct signature result. Require private key holders to keep their private keys safe.

2. Anti-tampering For digital signature and cryptographic protocols, the signature and the original file have formed a mixed whole data, which cannot be tampered with, thus ensuring the integrity of the data.

3. In the digital signature and password protocol, if serial number and time stamp are added to the signed message, replay attacks can be prevented.

4. Denial-proof digital signature can identify identity, and it is impossible to pretend to be forged. The signer cannot deny his signature. In order to prevent the denial of the receiver, in the digital signature and password protocol system, the receiver is required to return the message signed by himself to the other party or the third party, or the third party arbitration mechanism is introduced. In this way, neither side can deny it.

5. Confidentiality With the guarantee of confidentiality, the interception attack will not succeed. The message to be signed is properly encrypted to ensure confidentiality, which involves encryption or signcryption theory. Digital signatures can be used to verify the authenticity and integrity of documents. Digital signature uses powerful encryption technology and public key infrastructure to better ensure the authenticity, integrity and identifiability of documents. This process is very safe, and some governments have legislated to give digital signatures legal effect.