The digital counterpart of the handwritten signature is Digital Signature. Just as a paper document is authenticated with handwritten signature, digital signature authenticates the identity of the owner of the document in the digital world. It gives the assurance about the sender of the document as also the fact that the document has not been altered. Digital Signature is a kind of stamp which is very difficult to duplicate and forge.
The Information Technology Act, 2000 requires the use of Digital Signatures to ensure security and authenticity of all electronically filed documents. Digital Signature certificates (DSC) can be purchased from Certification Agencies (CAs) approved by the Controller of Certifying Authorities. Currently MTNL CA, TCS, IDBRT, Safetycrypt (Satyam), nCodeSolutions, NIC, and e-Mudhra are the authorised Certification Agencies for individuals in India. The Digital Signature Certificates (DSCs) generally have a validity of one year or two years and are legally admissible in a court of law.