Assume that a private internet requires that the messages at the application layer be encrypted and decrypted for security purposes. If we need to add some information about the encryption/decryption process (such as the algorithms used in the process), does it mean that we are adding one layer to the TCP/IP protocol suite? Redraw the TCP/IP layers (Figure 2.4 part b) if you think so.

Figure 2.4

Layer 5 Application Application Layer 4 Transport Transport Layer 3 Network Internet Network Interface Data link Layer 2 Layer 1 Physical Hardware Devices a. Original layers b. Layers used in this book