This paper describes about the design concept and the architecture of an economic VPN system which can perform fast crypto operations with cheap cost. The essence of the proposed system architecture is consisting of the system with two companion chips dedicated to VPN: one chip is a multi-purpose network processor for security machine and the other is a crypto acceleration chip which encrypt and decrypt network packets in a high speed. This study also addresses about some realizations that is required for fast prototyping such as the porting of an operating system, the establishment of compiler tool chain, the implementation of device drivers and the design of IPSec security engine. Especially, the second chip supports the most time consuming block cipher algorithms including 3DES, AES, and SEED and its performance was evaluated.