Digital signature is another application of public key encryption technology. The main way is that the sender of the message generates a new hash value (or message digest) from the message text. The sender encrypts this hash value with his own private key to form the sender's digital signature. Then, the digital signature will be sent to the recipient of the email as an attachment. The receiver of the message first calculates the hash value (or message digest) from the received original message, and then decrypts the digital signature attached to the message with the public key of the sender. If the two hash values are the same, the receiver can confirm that the digital signature belongs to the sender. Digital signature can realize the authentication and non-repudiation of the original message.

If you want to copy the digital signature, try to find a digital signature cloning tool on the Internet.