The Effect of the Initial Retransmission Timeout upon the Dictionary Attack Delay

this paper focuses on the effects of the TCP Initial Retransmission Timeout (RTO) and Round Trip Time (RTT) on one hand and the dictionary attack on the other hand. A dictionary attack model of two servers has been programmed and applied using TCL language. The delay time to find the correct password in the dictionary has been assigned to NS2 simulation network. The value of the initial RTO has been set to 0.5, 1, 3, 5, 10 seconds, with Round Trip Times (RTT) of 1, 5, 10, 20, and 50 milliseconds in the simulated network to study different situations. The results obtained were found to be consistent with previous findings associated to initial RTO values between 0.5s to Is for network performance. The additional values introduced here are for network security purposes as they represent the best values for which the attacker finds difficulty to accomplish dictionary attack.