Overhead effects of data encryption on TCP throughput across IPSEC secured network

Abstract The transmission control protocol (TCP) is an internet protocol used to send data across networks. When encrypted data are sent across networks, additional overhead is incurred. The data to be secured through encryption must be transformed from plain text to Ciphertext, resulting in data size increase. In this paper, the overhead effect of data encryption on TCP throughput across an internet protocol security (IPSec) network was investigated. In particular, we compared the additional data sizes of encrypted data to that of non-encrypted data, and their speed during transmission, respectively, using the iPerf3 simulator. Specifically, a comparative analysis between the actual transfer time of encrypted and non-encrypted data was investigated. The result showed that transmission times vary for different data sizes that were secured through encryption. Encrypted data had higher transfer time across the network. Additionally, the transfer time across the network was found to be consistent as data size increased with non-encrypted data. Encrypted data, on the other hand, were found to have inconsistent increase in data size with the same set of data sizes due to padding resulting in higher transfer time across thenetwork.