• Tinyos
• CC2420
• wireless sensors network
• security
• IEEE 802.15.4

During the last ten years, the presence of sensor networks in common life has become pervasive and sensor nodes are currently used in many areas of interest. One of the most common radio communication protocol designed for Personal Area Network (PAN) is described by the IEEE 802.15.4 standard, according to which data communication among devices can also be protected on a per frame basis, so making it possible to assure data authenticity and confidentiality, and security mechanisms can be configured in a flexible and effective way.
In this thesis work, the IEEE 802.15.4 security sublayer has been implemented. In particular, the TinyOS implementation for the tmote sky mote and the CC2420 chipset have been considered. The main goal of this work is to extend the above mentioned MAC layer implementation in order to make the IEEE 802.15.4 security mechanisms available, that is sending and receiving both ciphered and authenticated frames, by means of the security features provided by the CC2420 chipset.
All security data structures and procedures have been implemented, so making it possible to deal with different cryptographic keys usage and retrieval modes. During the development phase, some problems strictly related to computational and memory capacity shortage have been faced and properly addressed. Finally, the implemented security sublayer has been tested and evaluated by means of a simple application, which sends secured packets whose payload changes both in content and size.