Abstract: One new solution of the key exchange introduced in this paper does improve the IKE protocol. I}his solution not only allows the remote mobile users security access to the intranet and get the intranet information on the premise of no reduction in security, but also extent the ways of IKE authentication, making it more efficient in negotiation and more controllable. Besides, the solution develops a corresponding mobile VPN access system which supports both dynamic distribution of intranet IP address and the extension of user identity authentication. Thus the access server can easily control and manage the intranet IP-based access.

Key words: Mobile VPN, IPSec, IKE, Identity authentication