A novel improved compositive DDoS defence system

Based on the Probabilistic Packet Marking Scheme, a new Authenticated Packet Marking Scheme for IP trace-back is proposed. The novel scheme adopts a new dynamic probability value sequence to mark packets. Compared with PPM Scheme, the new scheme doesn't need the topology of network and it improves a lot on false positive, computational complexity and astringency. Meanwhile, propose one kind of DDoS attack defending solution which combines the source-end defense system with the improved scheme of packet marking that could both detect DDoS attack and track the source of attacks.