Research Article

Low-Rate DDoS Attack Detection Using Expectation of Packet Size

Algorithm 1

Low-rate DDoS attack detection using the expectation of packet size.
Input:
 Sample time ;
 Tolerance factor ;
 Obtained .
Output:
 Low-rate DDoS attack indicator .
() According to sample time , sample packets;
() Cluster packets by network flow;
() Determine the statistics of the packet size and calculate the mean packet size of each flow;
() Calculate the probabilities of network flows;
() Calculate the expectation of packet size and variance ;
() According to formula (10), set ;
() return