TRAP: A Three-Way Handshake Server for TCP Connection Establishment

Abstract

Distributed denial of service attacks have become more and more frequent nowadays. In 2013, a massive distributed denial of service (DDoS) attack was launched against Spamhaus causing the service to shut down. In this paper, we present a three-way handshaking server for Transmission Control Protocol (TCP) connection redirection utilizing TCP header options. When a legitimate client attempted to connect to a server undergoing an SYN-flood DDoS attack, it will try to initiate a three-way handshake. After it has successfully established a connection, the server will reply with a reset (RST) packet, in which a new server address and a secret is embedded. The client can, thus, connect to the new server that only accepts SYN packets with the corrected secret using the supplied secret.

Keywords

• TCP
• DDoS
• three-way handshake
• SYN flood attack
• Netfilter
• TCP options