Dynamic segmentation of network traffic through the use of Pre-Shared Keys (PSKs). Each defined network segment uses a different pre-shared key and a message authentication code (MAC)-signing algorithm to sign data packets with segment-specific MACs. As such, only those computer hosts/nodes that are in the network segment (i.e., have been assigned the same pre-shared key for generating and decoding the MAC signed data packets) are capable or reading the segment's network traffic. By implementing segment-specific MAC signed data packets, the present invention allows for confidential data transmission absent the need to encrypt the actual contents/data being transmitted.