Technical comparison analysis of encryption algorithm on site-to-site IPSec VPN

Virtual Private Network or VPN provide secure communication for remote users to access private data over public network. Although security is the main priority, the performance of VPN must also be considered. This paper presented how performance of VPN affected by choosing different encryption algorithms used by VPN devices. Analysis on performance of Windows Vista operating system was evaluated on a test-bed setup with combinations of encryption algorithms, different file sizes, and different protocols. Two encryption algorithms were used that are the AES 256 and 3DES and two hash algorithms that are MD5 and SHA-1 were used in the paper. Performance of the VPN is determined by the throughput parameter. Assessment task has found that different algorithms give different throughput readings. AES 256 - MD5 provide faster and more throughputs compared to other algorithm combination. Analysis also found that larger file size will reduce throughput of VPN, thus FTP performs faster than HTTP protocol.