A Digital Signature Certificate (DSC) is a secure digital key that certifies the identity of the holder, issued by a Certifying Authority (CA). It typically contains your identity (name, email, country, APNIC account name and your public key). Digital Certificates use Public Key Infrastructure meaning data that has been digitally signed or encrypted by a private key can only be decrypted by its corresponding public key. A digital certificate is an electronic "credit card" that establishes your credentials when doing business or other transactions on the Web.
Applications of DSC :
Employee Provident Fund
What is an eToken?
USB e-Token can be password protected so that Digital Signature is never lost when computer is formatted or internet explorer changed. A virus cannot affect USB Token, and the digital certificate stored would always be secure.