What layer handles encryption in a network?

The encryption in a network is primarily handled by the Presentation Layer.

The Presentation Layer, also known as Layer 6 in the Open Systems Interconnection (OSI) model, is primarily responsible for managing encryption and decryption of data in a network. This layer ensures that the data is in a format that the receiving system can understand. It transforms data into a form that the application layer of another system can use.

Encryption is a critical aspect of network security. It involves converting plain text into an unreadable format, known as cipher text, to prevent unauthorised access. The Presentation Layer uses encryption algorithms to transform the data. When the data reaches its destination, it is then decrypted back into its original format. This process is also managed by the Presentation Layer.

The Presentation Layer works closely with the Application Layer (Layer 7) and the Session Layer (Layer 5). The Application Layer interacts directly with the software application, requesting network services. The Session Layer, on the other hand, establishes, manages and terminates connections between applications.

While the Presentation Layer is primarily responsible for encryption, it's important to note that encryption can also occur at other layers. For instance, the Transport Layer (Layer 4) can also handle encryption in certain protocols like the Transport Layer Security (TLS) and Secure Sockets Layer (SSL). These protocols provide secure transport of data between applications.

In summary, while encryption can occur at different layers in the OSI model, it is primarily the responsibility of the Presentation Layer. This layer ensures that data is securely and correctly formatted for transmission and can be correctly interpreted by the receiving system.