A digital signature is used to authenticate digital documents by using computer cryptography. A digital signature not only validates the sender’s identity, but also ensures that the document’s contents have not been altered. Digital signature is based on digital certificates. Digital certificates are verifiers of identity issued by a trusted third party, which is known as a certification authority (CA). This works similarly to the use of standard identity documents in a non-electronic environment. It verifies that the source and integrity of the document is not compromised since the document is signed. A digital signature provides the following assurances: Authenticity, Integrity, and Non-repudiation.
