digital certificate

Public key certificate issued by a certification authority (CA) to guarantee that a user's identities and keys are valid and trustworthy. Digital certificates include the user's name, the public key of the user, the period over which the certificate is valid, and whether the key is to be used for data encryption, verification of digital signatures, or both. Commonly, digital certificates are used to verify that the sender of the message is the person they claim to be and also to provide the means with which to encrypt a reply. See public key infrastructure and trusted third party.