Abstract: Inter-domain routing system is the fundamental infrastructure of Internet. It consists of many interconnected autonomous systems (ASes) which configure and operate their routing policy independently. The uncoordinated routing decision can cause various problems such as routing oscillations, routing security and traffic engineering failure. To detect and remove the routing policy conflict, multi-ASs cooperation is needed. For competitive purpose, ISP always keeps some information confidential such as routing policy, network topology and this requirement of privacy preserve hinders the cooperation among ISP. Due to the lack of effective coordinative mechanism for confidential information access, the cross-domain routing policy management can not be implemented. To improve the cooperative ability of ISP, the authors design a multi-AS-cooperation-oriented method for routing policy consistency analysis based on disperse logarithm hypothesis, which can detect the inconsistency existing among multi ASs routing policy without leaking the confidential information of policy. Compared with the solution based additively homomorphic asymmetrical encrypt function, this method need not an oblivious third party and has lower computing and communication cost. This method need not modify the BGP routing protocol, so it is easier to deploy and cheaper to implement. It can be used in many applications such as routing policy conflict detection, routing validation, routing monitor and cooperative intrusion detection.