digital certificate

A digital certificate is an electronic credit card that establishes a user’s credentials when doing business or other transactions on the Web. It is issued by a Certificate Authority (CA). It contains the user’s name, a serial number, expiration dates, a copy of the certificate holder’s public key (used for encrypting and decrypting messages and digital signatures), and the digital signature of the certificate-issuing authority so that a recipient can verify that the certificate is real.