Virtual vpn in the cloud

2.3
 
IPSec complexities 
As stated by Shreyas Srivatsan et al. in [15], IPSec causes configuration 
complexity and inconsistent implementations. Despite having the advantage of operating 
transparently to applications in the host system, the complexity of the protocol has led to 
interoperability problems between systems. The main reason for complexity is the usage of 
multi-purpose certificates in public key authentications [15]. Thus [15] presents an IPSec 
configuration compiler, Simple-VPN to tackle these IPSec complexities. Simple-VPN 
generates authorization only certificates limited to the machine that is a part of the VPN, 
rather than to the identity of the user. The compiler has been designed to support cross-

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platform implementations, flexibility to end-users by substantiating useful extensions and 
compatible to the addition of new IKE features. This paper provides an insight into the 
complications involved with the utilization of public key authentication in the form of digital 
certificates for IPSec VPN implementations.
Current research focuses on the avoidance of complexities in the cloud, thus 
focusing on Pre-Shared Key authentication for key distribution to yield better VPN 
performance in cloud also giving a detailed literature review on the various key distribution 
mechanisms available. 
2.4
 
Analysis of Encryption Algorithms on site-to-site VPNs 
The authors in [16] implement a site-to-site VPN on Cisco routers in a Windows
 
Vista environment giving an explanation of how VPN performance is affected hinging on to 
the optimal selection of different encryption algorithms. Among the different combinations 
of encryption, AES256 and 3DES, and hashing algorithms, SHA1 and MD5, used AES256-
MD5 system displayed the best throughput performance in comparison to the others. Further 
deduction revealed that AES256 performed better that 3DES and MD5 superior to SHA-1. 
This paper comprehends the need for optimal algorithm preference to obtain higher network 
throughput. 
Likewise, the current research yields similar outputs, stating AES algorithms 
with different block sizes perform better than 3DES while MD5 outperforms SHA but in a 
Linux-based environment on a cloud infrastructure.