Xingang Wang Dengguo Feng Zhen Xu Honggang Hu Mediator-Free Secure Policy Interoperation of Exclusively-Trusted Multiple Domains. 248-262 2008 ISPEC http://dx.doi.org/10.1007/978-3-540-79104-1_18 conf/ispec/2008 db/conf/ispec/ispec2008.html#WangFXH08