What mechanism does Kerberos utilize to issue tickets?

The Key Distribution Center (KDC) is responsible for issuing tickets in Kerberos. Tickets are generated by the ticket-granting service, which is typically a component of the KDC. The authentication service simply verifies the identity of the user. X.509 certificates and certificate authorities are not part of the Kerberos protocol. While the ticket-granting service generates the ticket, it is ultimately issued by the KDC.

The KDC issues tickets in Kerberos using a two-part process. First, the user's client sends a request to the KDC for a ticket-granting ticket (TGT) that can be used to request other tickets. The KDC verifies the user's identity and generates a TGT if the user is authorized.

Second, when the user needs to access a particular resource or service, the client uses the TGT to request a service ticket from the KDC for that resource or service. The KDC generates a service ticket that includes the user's identity, the requested resource or service, and a session key that can be used to encrypt communications between the user and the resource or service. The service ticket is then sent back to the user's client, which uses it to authenticate to the resource or service.