To obtain a strong security system based on wireless sensor networks (WSNs), cryptographic-based protocols are desired. Generally, the use of strong security mechanisms demand intensive use of limited resource, particularly memory storage and energy to provide defense services against malicious attacks. Risks detection in WSNs rely upon the behavior of every single sensor node in the system, and in the case of abnormal node behavior, the system protects the travelling packets on the network via a high level of security mechanisms such as a trusted key management algorithm. In this paper, we compare existing schemes and present a new hybrid security scheme suitable for maritime coastal environment-based WSNs. This scheme tackles the issues of memory storage of encryption keys based on a trusted node configuration, called a leader node, which works as a trusted third party for both the node joining and the node revoke processes. This security mechanism is implemented and tested in real time on a Waspmote sensor testbed platform. Copyright (c) 2016 John Wiley & Sons, Ltd.To obtain a strong security system based on wireless sensor networks (WSNs), cryptographic-based protocols are desired. Generally, the use of strong security mechanisms demand intensive use of limited resource, particularly memory storage and energy to provide defense services against malicious attacks. Risks detection in WSNs rely upon the behavior of every single sensor node in the system, and in the case of abnormal node behavior, the system protects the travelling packets on the network via a high level of security mechanisms such as a trusted key management algorithm. In this paper, we compare existing schemes and present a new hybrid security scheme suitable for maritime coastal environment-based WSNs. This scheme tackles the issues of memory storage of encryption keys based on a trusted node configuration, called a leader node, which works as a trusted third party for both the node joining and the node revoke processes. This security mechanism is implemented and tested in real time on a Waspmote sensor testbed platform. Copyright (c) 2016 John Wiley & Sons, Ltd.