Wireless sensor networks (WSN) are rapidly expanding their attractiveness in both military and civilian applications, imposing the need for effective security strategies/mechanisms. Since sensor networks in many circumstances operate with sensitive data or function in hostile unattended environments, it is essential that these security issues to be addressed in each and every lifecycle phase. In this paper we considered that a new phase (self-destruction) must be included as a final stage in the WSN lifecycle in order to assure the confidentiality regarding information like: network topology, type of measurement data gathered by sensors, encryption/authentication algorithms and key-exchange mechanisms, etc. that can be unveiled otherwise through reverse engineering methods. Moreover, we presented a new procedure that can be followed to implement this new lifecycle phase on a very common and used network topology - mesh.