A digital signature is an electronic form of a signature that can be used to authenticate the identity of the sender of a message or the signer of a document, and also ensure that the original content of the message or document that has been sent is unchanged. Digital signatures are easily transportable and cannot be imitated by someone else. The ability to ensure that the original signed message arrived means that the sender cannot easily disclaim it later.Digital Signatures are used in India for online transactions such as Income Tax E-Filing, Company or LLP Incorporation, Filing Annual Return, E-Tenders, etc. With E-Return filing becoming mandatory for Income Tax Assesses with an income of over Rs.5 lakhs per annum, the requirement and prevalence of Digital Signatures has increased manifold.