What is the difference between a digital certificate and a public key?
In cryptography, a public key is a large numerical value that is used to encrypt data. The key can be generated by a software program, but more often, it is provided by a trusted, designated authority and made available to everyone through a publicly accessible repository or directory.
Digital certificates include the public key being certified, identifying information about the entity that owns the public key, metadata relating to the digital certificate and a digital signature of the public key created by the issuer of the certificate.
What is the most common use case for digital certificates?
They are most commonly used for initializing secure SSL connections between web browsers and web servers.
What is a certificate authority (CA)?
CAs are considered trusted third parties in the context of a PKI (public key infrastructure); using a trusted third party to issue digital certificates enables individuals to extend their trust in the CA to the trustworthiness of the digital certificates that it issues.