| Wireless commodity devices become an inseparable part of our daily life, leading to increasing demand and diverse requirements on the services provided by commodity devices. In particular, security is an important aspect attracting much attention in both research and industry. Supporting secure communication and providing dependable wireless services among wireless commodity devices are crucial to support data transmission confidentiality, data integrity, and device authentication in people's daily lives.;First of all, the nature of broadcast-based communication has made wireless networks vulnerable to jamming attacks and radio interference due to the increasingly flexible programming interfaces of commodity devices for building jammer and the crowded radio environment. To ensure the dependability of wireless services, we address the problem of determining the physical locations of jamming attackers/radio interference coexisting in wireless networks by leveraging the network topology changes caused by jamming. As a result, learning the location of the jammers enables the network to exploit a wide range of defense strategies.;Furthermore, although much effort has been spent on securing wireless communication, the wireless communication itself can also be exploited to enhance the security in wireless commodity devices. Since traditional cryptographic-based methods are not always applicable in dynamic mobile wireless environments for securing communication, using physical layer information of radio channel to generate keys secretly among wireless devices has become an alternative. We propose a framework for collaborative key generation among a group of wireless devices leveraging Received Signal Strength (RSS) due to its readily availability in wireless infrastructure. Our experiments in both outdoor and indoor environments confirm the feasibility of using RSS for group key generation among multiple wireless devices under various mobile scenarios.;Besides securing communication in wireless networks, to support the widespread adoption of distributed data storage in wireless networks, secure data storage must be achieved. We study the frequency-based attack, which exploits additional knowledge of domain values and exact/approximate occurrence frequencies to crack the encrypted data. To cope with frequency-based attacks, we propose a data encryption strategy based on 1-to-n substitution via dividing and emulating techniques such that an attacker cannot derive the mapping relationship between the encrypted data and the original data based on their knowledge of domain values and their occurrence frequency. |
