Which layer of the OSI model is involved in data encryption and decryption?

The Presentation Layer of the OSI model is responsible for the formatting, encryption, and decryption of data. This layer acts as a translator between the application layer and the network layer by transforming data into a format that can be understood by both the sender and the receiver. When it comes to encryption, this layer ensures that sensitive data is secured before it is transmitted over the network. It is also responsible for managing data compression and translation services, which prepares the data for application-specific use.

In the context of the OSI model, the Transport Layer focuses on end-to-end communication and reliability, managing the data transfer between host systems without delving into the data's specific content or form. The Session Layer establishes, manages, and terminates connections between applications, but does not perform the actual encryption or decryption of data. The Application Layer interacts directly with end-user applications but is not concerned with the underlying encryption processes. Therefore, the Presentation Layer is uniquely positioned within the OSI model to handle encryption and decryption tasks, making it the correct answer.