Naturally, the Internet as an open network allows millions of users to interact each other. Furthermore, the giant network vulnerable to various malicious activities that potentially causes many (losses) for both resources and humanity. In order to reduce the potential attacking activities, Internet Engineering Task Force has standardized a network level security so-called IP Security. The key process behind the IP Security is a Security Association that is identified by Security Parameter Index. The initiation of Security Association performance depends on the encryption algorithm used. Hence, the performance of the algorithm candidate is an important consideration. This paper aims to evaluate some encryption algorithm to be used in IPv6 network. Results of the experiments shows that ECP 384 based on the elliptic curve algorithms outperforms than the traditional algorithm such as MODP 1024 and MODP 3072.MATEC Web of Conferences 218, 03001 (2018) https://doi.org/10.1051/matecconf/201821803001 ICIEE 2018There are three aspects on the network security including confidentiality, data integrity and availability. Currently there are several methods in network security to serve the three aspects. The method is usually developed based on the security hole that will be faced. One of the methods used in network security is the IP-Based security system [3]. This protocol can co-exist with IP datagrams to support secure data transmission over unprotected public networks. IPSec is a set of protocols that provide security for Internet communication on the network layer [4]. The most common use of IPSec is to provide a virtual network or VPN (Virtual Private Network) that is used between gateway-to-gateway, host-to-host, or end-to-end [5]. IPSec consists of several subprotocols, they are Authentication Header (AH), Encapsulating Security Payload (ESP), and Internet Key exchange (IKE). AH and ESP aims to provide cryptographic services, while IKE handles the Security Association parameter management.One of the considerations on the implementation of IPSec with IKEv2 is the selection of key exchange cryptography algorithms. This is very important because the key exchange is the process of connecting two or more hosts that want to connect in a secret communications network but through the public network without having to enter into an agreement between the parties involved. In addition, choosing the right key exchange algorithm will affect the performance of the exchange speed, the performance of the encryption strength and the performance of the network itself. This research will evaluate some candidates to obtain the best cryptographic algorithm to be implemented on IPSec and IKEv2.