Alice wants to communicate with Bob in a secure fashion. We shall describe all the necessary steps to establish the communication using the Certification Authority
Alice creates a public/private key pair using a public key algorithm like RSA. Then, she creates a Certificate Signing Request (CSR), which is the Certificate just before to be signed by the Certification Authority. In the Certificate, there is information about the identity of the user, such as the name, address, telephone number and e–mail. Certificates can be used to authenticate not only people but also entities in general, such as a WWW server or a software agent. In this case, the information in the Certificate would be the URL of the WWW server, the WWW Administrator details and so on. Finally, the public key is added in the CSR.