What is the goal of the Needham-Schroeder protocol used in SESAME?

The Needham-Schroeder protocol is designed primarily to establish secure communication between entities in a network. This protocol utilizes a ticket-based system to ensure that the communicating parties can authenticate each other before a secure session is initiated. The focus of the protocol is on establishing the validity of credentials and ensuring that messages exchanged between parties remain confidential and untampered with during their transmission.

While the protocol does pertain to the principles of managing identities in a network, its primary goal revolves around securing communication channels rather than user identity management or creating ticket granting mechanisms specifically. It also does not concentrate on facilitating secure vendor connections, which is outside its main function.

Overall, the main purpose of the Needham-Schroeder protocol aligns with ensuring secure and authenticated communications, thereby making this option the most appropriate among the choices provided.