Composable distributed access control and integrity policies for query-based Wireless Sensor Networks

In much the same way as the Global Positioning System (GPS) was initially intended as a navigation system for military use, current Wireless Sensor Networks (WSNs) tend to be dedicated to a particular purpose and for the exclusive use of a particular organization. Thus, WSN security has focused in large part on encryption and authentication schemes to protect data during transmission and ensure only authorized users are granted network access. However, just as GPS has become an indispensable resource for military and civilian use it is expected that WSNs will become an essential sensing resource that must support a vast number of users.; This will require security measures mirroring the security concepts of typical secured computer networks in which authenticated users are only authorized to access certain data within the system. WSNs will need to similarly restrict access to data, enforcing security policies to protect data within WSNs, even though WSN nodes face severe power, memory, computational, and communication limitations. To date, WSN security has largely been based on encryption and authentication schemes.; The WSN Authorization Specification Language (WASL), a mechanism-independent composable WSN policy language, takes into account the severe resource constraints of WSN nodes. The language is itself specified and implemented with a JavaCC(TM) grammar-parser for security policy input and a policy compiler built using Java(TM) code.; WASL is capable of specifying arbitrary and composable security policies that span and integrate multiple WSN policies. The construction, hybridization, and composition of well-known models is demonstrated to preserve security, sustaining confidentiality in Bell-LaPadula's model, integrity in Biba's strict integrity model, and conflict of interest avoidance in the Chinese Wall.; Using WASL, a multi-level security policy for a 1000 node network requires only 66 bytes of memory per node using a naive data compression scheme. A policy of this size can reasonably he distributed throughout a WSN periodically. The compilation of a variety of policies and policy compositions are shown to be feasible using a notebook-class computer not unlike that expected to be performing typical WSN management responsibilities.; A system implementing WASL is secure as defined by the security model. It is also be more flexible in that a policy file update is all that is required to modify the accesses permitted any given user. The policy can be additionally modified to permit inter-network accesses with no more impact on the WSN nodes than any other policy update.