Secure device to device communication

Sammanfattning: Since wireless communication has become a standard feature in the daily life, smartphones and tablets among other things are integrated with the Bluetooth technology. While in some parts of the day wireless communication can be used for searching the internet and share information on social networks without the need of having a secure connection, there are some other parts where the security might become of high importance. When the technology gets integrated in companies the security problem becomes more evident. This is because when the radio signals spread in the medium they can be accessed by anyone that is in reach in the network and the information that was sent may not be intended for everyone. To secure the network from unintended users becomes important when handling fragile information, which companies may deal with daily.  This paper gives an introduction on which security features and techniques that already exist in some personal area networks. From this it has been clear that a security feature could be implemented on the baseband layer of Bluetooth to increase the secrecy during the transmission since at the moment security is only implemented on higher layers using encryption algorithms.  This paper proposes a conceptual idea of improving the secrecy in the network by using a wiretap code that is implemented before the error-correction coding in the Bluetooth's baseband. By disabling the ARQ scheme in Bluetooth one can modulate the channel as a Packet Erasure Channel that will lose packet with a certain probability. By using a nested code structure, the message can then be securely sent by using a higher rate than what the eavesdropper can recover due to the amount of errors the received signal will have. The performance of the concept is evaluated with the secrecy throughput, secrecy outage and the leakage.