A Digital Signature Certificate is the digital equivalent of your hand written signature, issued by a Licensed Certifying Authority (CA) and are legally valid in India. It may include information like mobile number and PAN number in encrypted form. It is used for digitally signing documents online. Class 3 DSC is now used for all purposes, including MCA21 e-Filing, Income Tax e-Filing, GST, EPFO,  TRACES, CERSAI 2.0, e-tenders & e-procurement, etc.,