A digital certificate is public key and other information that is digitally signed by a certification authority (CA). The certification authority provides the ability for a receiver of a digitally signed document or encrypted information to be sure the person who signed the document or sent the information really is the person they claim to be. The digital certificate includes:
- The holder's name
- A serial number
- Expiration dates
- The certificate owner's public key.
- The CA's digital signature
The digital certificate works as an identifier for people or entities doing business on the internet. It can be used as proof that the holder has a right to access information or to establish identity. Digital certificates can be used to determine whether a person who digitally signed a message really did sign or send the message. They may also be used to encrypt data and send it so only the intended person can read the message with their private key. Digital certificates may be made publically available so user's can look up public keys to verify signatures.