BSD-Guard: A Collaborative Blockchain-Based Approach for Detection and Mitigation of SDN-Targeted DDoS Attacks

Algorithm 2

Elastic mitigation based on graylist.

Input:Graylists on blockchain
Output:flow_mod message
(1)	Group the graylist by victim controller ID
(2)	for Each victim controller do
(3)	Calculate the and
(4)	for Each suspect switch do
(5)	Calculate the of each suspect port
(6)	Construct the flow_mod message according to graylist and
(7)	Issue the flow_mod message to switches
(8)	end for
(9)	end for