A bran-new lattice based cross-domain model is proposed to solve the shortcomings of the existing authentication model. Firstly, using the lattice theory, this model builds credit-domain alliance and user alliance on the two dimensional coordinates to avoid the abuse of centralized plans. Secondly, it uses the superiority thought of the existing authentication system to strengthen the integrity of the model. Finally, the detailed work flow, formula, domain disposal, extended algorithm, and identity-based Stealth transport protocols of the new model are drafted. It ensures the user’s identity information and privacy. After the certification and analysis, this model proved to have a good Practical character and an extremely large extension space.