Recent trends show increased demand for content-rich media such as images, videos and text in ad-hoc communication. Since such content often tends to be private, sensitive, or paid for, there exists a requirement for securing such information over resource constrained ad hoc networks. In this work, traditional data security mechanisms, existing ad hoc secure routing protocols and multilevel security are first reviewed. Then a new system, called the Multilevel Adaptive Security System, which incorporates the multilevel security concept at both the application layer and the network layer, is proposed to provide adaptive security services for data and routing processes.

MLASS is composed of two subsystems: Content-Based Multi-level Data Security (CB-MLDS) for content-rich data protection and Multi-Level On-demand Secure Mobile Ad hoc Routing (MOSAR) for secure route selection. The structure of each sub-system is explained in detail; experiments for each sub-system were conducted and the performance was analyzed. It is shown that MLASS is a practical security solution that is flexible enough to adapt to a range of security requirements and applies appropriate level of security services to data and its distribution over ad hoc networks. MLASS provides a balance between security, performance and resource.