Abstract: A lattice model of the global security system is presented, and its expression and construction are discussed in this paper. Based on the lattice model, a global security system model with multiple security classes for ODP environment is derived, in which security domains are labeled as different security class, and the whole system are organized with multiple security classes and hierarchy.

Key words: open distributed processing (ODP), global security system, security object, security domain, security association, security classes, lattice, security policy