Which layer is responsible for data encryption and session management?

The Application Layer is responsible for data encryption and session management. This layer interacts directly with user applications and enables network services to be used effectively by those applications. It provides protocols that facilitate encryption for securing data during transmission, ensuring confidentiality and integrity when necessary.

For instance, protocols like HTTPS, which is an extension of HTTP, provide a mechanism for encrypting data exchanged between web browsers and servers, thus protecting sensitive information such as passwords and credit card numbers. Furthermore, session management, including establishing, maintaining, and terminating sessions between applications, occurs at this layer, allowing for a seamless user experience across a network.

Other layers, such as the Network Access Layer, the Transport Layer, and the Internet Layer, do not handle encryption and session management directly. The Network Access Layer focuses on the physical transmission of data over different media, the Transport Layer ensures reliable end-to-end connections and data transfer between devices, and the Internet Layer directs data packets across different networks. Each of these layers plays a critical role in network communication, but they do not manage encryption or session handling like the Application Layer does.