Digital signatures are equivalent to traditional handwritten signatures in many respects; properly implemented digital signatures are more difficult to copy than the handwritten type. Digital signature are implemented using cryptography. Digital signatures can also provide acknowledgement, meaning that the signer cannot successfully claim they did not sign a message, while also claiming their private key remains secret. Digital signatures are regularly used in USA, European countries and India in government as well as private offices. In India certificate called Digital Signing Certificate (DSC) is widely used for e-filing the business related documents and income tax return filing etc.