A research on the impact of encryption algorithms on the quality of VPN tunnels’ transmission

Abstract

The following article presents the results on the impact of encryption algorithms and the cryptographic hash function on the QoS (Quality of Service) transmission in a computer network. A network model supporting data encryption using the AES algorithm and the MD5 and SHA hash functions used in VPN tunnels was designed and tested. The influence of different data length on the quality of transmission in a secured network was studied. The measurements and tests of networks were performed according to two methodologies ITU-T Y.1564 and RFC 2544. The impact of the data encryption mechanism on bandwidth, data loss and maximum delays was examined. The secured network tests were performed with different combinations of encryption algorithms and hash functions of the VPN tunnel in the ESP (Encapsulating Security Payload) transport mode.