A Hybrid Port-Knocking Technique for Host Authentication

Abstract

This chapter presents the detail description of a Port-Knocking (PK) technique, which should avert all types of port attacks and meets all other network security requirements. The new technique utilizes four well-known concepts, these are: PK, cryptography, steganography, and mutual authentication; therefore, it is referred to as the Hybrid Port-Knocking (HPK) technique. It is implemented as two separate modules. One is installed and run on the server computer, either behind the network firewall or on the firewall itself, and the other one is installed and run on the client computer. The first module is referred to as the HPK server, while the second is the HPK client. In terms of data processing, the technique consists of five main processes; these are: request packetization and transmission, traffic monitoring and capturing, mutual authentication, request extraction and execution, and port closing. The HPK technique demonstrates immunity against two vital attacks, namely, the TCP replay and Denial-of-Service (DoS) attacks.