Digital Certificate is an encrypted and digitally signed attachment that authenticates a user on the Internet/ intranet. A digital certificate is issued by a certificate authority (CA), and attests to the legitimacy of an online transfer of information, or other sensitive materials through the use of encryption.
A digital certificate includes the sender's name, a serial number, expiration dates, a copy of the certificate holder's public key, and the digital signature of the issuing CA.A digital certificate holder has both a private key and a public key. The private key is held only by the user and is for signing outgoing messages and decrypting incoming messages.