A Digital Signature Certificate,  is just like a handwritten signature only, establishes the identity of the sender filing the documents through the internet which the sender can not revoke or deny. A Digital Signature Certificate is not only a digital equivalent of a handwritten signature it adds extra data electronically to any message or a document where it is used to make it more authentic and more secure. Digital Signature ensures that no tampering of data is done once the document has been digitally signed.