Abstract. For the application of large-scale mobile agents in a distributed environment, where a large number of computers are connected together to enable the large-scale sharing of data and computing resources, security and efficiency are of great concern. In this paper, we present secure route structures and corresponding protocols for mobile agents dispatched in binary to protect the dispatch route information of agents. The binary dispatch model is simple but efficient with a dispatch complexity of O(log2n). The secure route structures adopt the combination of public-key encryption and signature schemes and expose minimal route information to hosts. The nested structure can help to detect attacks as early as possible. 1 Inroduction Mobile agents are computational entities that are autonomous, mobile and flexible that can facilitate parallel processing. Very often, a mobile agent acts on behalf of its owner to migrate through the distributed network, completes the specified tasks...