🔑 Key Distribution Center (KDC)

The Key Distribution Center (KDC) is a central component of the Kerberos authentication protocol. It plays a crucial role in managing the keys and tickets necessary for secure authentication of users and services in a network. The KDC is responsible for issuing authentication and service tickets, ensuring that communications between clients and servers are secure.

🗂️ Components of the KDC

The KDC consists of two main services :

1. Authentication Service (AS)
2. Ticket Granting Service (TGS)

📎 Authentication Service (AS)

The Authentication Service (AS) is the first step in the Kerberos authentication process. Its responsibilities include :

1. Initial Authentication: The AS verifies the identity of the user when they first log in.
2. Issuing the Ticket Granting Ticket (TGT): After authenticating the user, the AS issues a TGT, which is a special ticket used to obtain other tickets without having to re-authenticate.

🎟️ Ticket Granting Service (TGS)

The Ticket Granting Service (TGS) is the second step in the Kerberos authentication process.

🛠️ Technical Functioning

Key Management

The KDC manages keys in several ways to ensure the security of communications :

Master Key: The master key is used to encrypt and protect other keys stored in the KDC database. It is typically derived from an administrator password and used to secure the principal keys of each service account.

Session Keys: Session keys are randomly generated for each authentication session. They are used to encrypt communications between the client and the service server.

Service Keys: Each network service has a secret key shared with the KDC. These keys are used to encrypt service tickets.