A digital signature or digital signature scheme is a type of asymmetric cryptography. For messages sent through an insecure channel, a good implementation of digital signature algorithm is one that makes the receiver believe that the message was sent by the claimed sender, and trust the message.
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.
Digital signatures are often used to implement electronic signatures, a broader term that refers to any electronic data that holds a meaning of a signature, but not all electronic signatures use digital signatures. In some countries, including the United States, and in the European Union, electronic signatures may have legal significance. In India electronic signature do not have any legal significance but digital signature does have legal validity and considered as legally valid signature as per the information technology act, 2000.