The need for security in embedded systems has strongly increased since several years. Nowadays, it is possible to integrate several processors in a single chip. The design of such multiprocessor systems-on-chip (MPSoC) must be done with a lot of care as the execution of applications may lead to potential vulnerabilities such as revelation of critical data and private information. Thus it becomes mandatory to deal with security issues all along the design cycle of the MPSoC in order to guarantee a global protection. Among the critical points, the protection of the communications is very sensible as most of the data are exchanged through the communication architecture of the system. This paper targets this point and proposes a solution with distributed enhancements to secure data exchanges and to monitor communications within a MPSoC. In order to validate our contribution, a case study based on a generic multiprocessor architecture is considered.