A digital signature is a mathematical scheme that validates the integrity or authenticity of a given digital document or digital message. Digital signature certificates are the electronic or digital equivalent of paper certificates. Digital signature certificates validate your digital signature and for affixing digital signatures to e-documents digital signature certificates are required. Generally certificates are used to prove the identity of a person for particular purpose like driving license or passport or pan card or others. Similarly digital signature certificates are used to prove the identity of the person digitally to avail information or services on the internet and to sign certain documents digitally.