Which component of the KDC generates the encrypted time-stamped Ticket Granting Ticket (TGT)?

The Authentication Server (AS) is responsible for generating the encrypted time-stamped Ticket Granting Ticket (TGT) in a Key Distribution Center (KDC) environment. The primary function of the AS is to authenticate users and issue TGTs, which are used to request access to various services within a network.

When a user first logs in, they typically present their credentials to the AS. Upon successful authentication, the AS generates a TGT, which contains a session key and is encrypted using the KDC's secret key. The TGT allows the user to request service tickets from the Ticket Granting Server (TGS) without needing to re-enter their credentials, thereby facilitating a seamless access process to various resources in the network.

The other options do not fulfill the specific role of generating the TGT. The Ticket Granting Server is designed to provide service tickets upon receiving a valid TGT, while the Session Management Server and User Credential Server are not standard components specifically associated with the process of issuing TGTs in typical KDC frameworks. Thus, the Authentication Server is unequivocally the correct choice for this function.