MhRep: Multi-hop Replication Scheme for Data Survival in Unattended Wireless Sensor Networks

Unattended Wireless Sensors Networks (UWSNs) are emerging Wireless Sensor Networks (WSNs) characterized by periodic absence of trusted entities, like the Sink Collectors. The time periods with no sink attendance, force the network sensors to locally store collected data until the next sink visit. This means that data collection is not performed in real time, but it falls at regular intervals. Such conditions define a different paradigm regarding traditional WSNs and introduce several new security issues, data survival above all. At the best of our knowledge, only two strategies were proposed to mitigate mobile adversary data deletion attack : encryption protocols (implementing backward and/or forward secrecy) and replication. While encryption protocols can impose an extensive computational effort and experience several security issues (like key exposure), replication schemes seem to capture a renewed interest from researchers, since their power requirement seem compatible with the constraints of wireless sensors. In this paper we focus on a new replication scheme and compare its performances with some other proposals, previously presented in literature. The schemes share some model assumptions, in terms of network and adversary attack strategy and objectives.