part from the ability to provide non-repudiation of messages, The digital signature also provides message authentication and data integrity. Let us briefly see how this is achieved by the digital signature -Message authentication – when the verifier validates the digital signature using the public key of a sender, he is assured that the signature has been created only by the sender who poses the corresponding secret private key and no one else.
Since it is assumed that only the signer has knowledge of the signature key, he can only create a unique signature on a given data. The receiver can present data and the digital signature to a third-party as evidence if any dispute arises in the future.
in case an attacker has access to the data and modifies it, the digital signature verification at receiver end fails. The hash of modified data and output provided by the verification algorithm will not match. Hence, the receiver can safely deny the message assuming that data integrity has been breached.
Out of all cryptographic primitives, the digital signature using public key cryptography is considered as a very important and useful tool to achieve information security.