BGP (border gateway protocol) security is very important to the inter-domain routing security. Many solutions have been proposed, but none has been deployed until now. This paper analyzes the main problems of these approaches. It studies the AS (autonomous system) topology of the Internet, especially the rich-club property, and gives the notion of the AS alliance. It proposes SE-BGP (security enhanced BGP) as a new way for BGP security. An alliance-based security architecture, and a new trust model-TTM (translator trust model) for SE-BGP are constituted. An authentication scheme based on TTM is also designed. Furthermore, the way of how to extend the BGP protocol is considered. The SE-BGP has strong ability of security and good scalability, and the number of the used certificates is about 1% of the traditional solutions.