A digital signature is used to authenticate the identity of the sender to the receiver to a limited extent in order to verify the integrity of the message. It is necessary to the sender’s public key by the prior knowledge or by trusted third party. A digital signatures is created by using the sender’s private key to hash the entire message. The recipient uses the sender’s public key to verify the integrity of the message. To sign the message, sender append their signature to the end of the message and encrypt using the recipient’s public key.
Recipient decrypt the message using their own private key and verify the sender’s identity and the integrity of the message by decrypting the sender’s digital signatures using the sender’s public key.
Digital Certificate :
It can used to verify the unaltered delivered message and the identity of the sender by the public key. A digital certificate is issued by the a known third party to bind an individual to a public key. The digital signature is digitally signed by the certification authority with it’s private key which provides the confirmation fact who it claims to be.