Answer:
In the presentation layer of the OSI reference model provides a variety of coding and functions that can be applied in application layer data. Information send by the application layer are ensured by these functions. As, presentation layer is the important layer in the OSI reference model because it is responsible for important services like data compression, data conversion, decryption and encryption.
Encryption at gateway is defined as, when the important data is first encrypted using protocol and then it is transferred in the network. And gateway re-director operates in the presentation layer.
