Wireless Sensor Networks: Security Requirements - Security Management, Availability, and Quality

1.5 Secure Management

Management is required in every system that is constituted from multi components and handles sensitive information. In the case of sensor networks, we need secure management on base station level; since sensor nodes communication ends up at the base station, issues like key distribution to sensor nodes in order to establish encryption and routing information need secure management. Furthermore, clustering requires secure management as well, since each group of nodes may include a large number of nodes that need to be authenticated with each other and exchange data in a secure manner. In addition, clustering in each sensor network can change dynamically and rapidly. Therefore, secure protocols for group management are required for adding and removing members, and authenticating data from groups of nodes.

1.6 Availability

Availability ensures that services and information can be accessed at the time that they are required. In sensor networks there are many risks that could result in loss of availability such as sensor node capturing and denial of service attacks. Lack of availability may affect the operation of many critical real time applications like those in the healthcare sector that require a 24 / 7 operation that could even result in the loss of life. Therefore, it is critical to ensure resilience to attacks targeting the availability of the system and find ways to fill in the gap created by the capturing or disablement of a specific node by assigning its duties to some other nodes in the network.

1.7 Quality of Service

Quality of Service objective is a big headache to security. And when we are speaking about sensor networks with all the limitations they have (reference the second part of the article to find out more on limitations), quality of service becomes even more constrained. Security mechanisms must be lightweight so that the overhead caused for example by encryption must be minimized and not affect the performance of the network. Performance and quality in sensor networks involve the timely delivery of data to prevent for example propagation of pollution and the accuracy with which the data reported match what is actually occurring in their environment.  

2. Conclusions

In this third part of Wireless Sensor Networks, I analyzed the security requirements that should be met to better protect sensor networks from adversaries; confidentiality, authentication, integrity, freshness, secure management, availability and quality of service were discussed. As you may see, the same security objectives that exist in conventional systems are needed for sensor networks as well. The difference is that the security objectives here are addressed in the context of sensor nodes characteristics like their architecture and limitations.

I hope you found the information provided here useful. Moving on, the next article will discuss the security attacks that can be launched against sensor networks and possible countermeasures that are proposed by researchers.