Security in Mobile Wireless Sensor Networks – A Survey <s> B. SKC-based Distributed Data Access Control <s> A key distribution scheme for dynamic conferences is a method by which initially an (off-line) trusted server distributes private individual pieces of information to a set of users. Later any group of users of a given size (a dynamic conference) is able to compute a common secure key. In this paper we study the theory and applications of such perfectly secure systems. In this setting, any group of t users can compute a common key by each user computing using only his private piece of information and the identities of the other t - 1 group users. Keys are secure against coalitions of up to k users, that is, even if k users pool together their pieces they cannot compute anything about a key of any t-size conference comprised of other users.First we consider a non-interactive model where users compute the common key without any interaction. We prove a lower hound on the size of the user's piece of information of (k+t-1 t-1) times the size of the common key. We then establish the optimality of this bound, by describing and analyzing a scheme which exactly meets this limitation (the construction extends the one in [2]). Then, we consider the model where interaction is allowed in the common key computation phase, and show a gap between the models by exhibiting an interactive scheme in which the user's information is only k + t - 1 times the size of the common key. We further show various applications and useful modifications of our basic scheme. Finally, we present its adaptation to network topologies with neighborhood constraints. <s> BIB001 </s> Security in Mobile Wireless Sensor Networks – A Survey <s> B. SKC-based Distributed Data Access Control <s> Sensor networks have been an attractive platform for pervasive computing and communication. Due to the lack of physical protection, however, sensor networks are vulnerable to attacks if deployed in hostile environments. When a sensor network is under attack, the most fundamental concern is that information communicated or stored in the network remains safe. The past research has focused on securing information in communication, but how to secure information in storage has been generally overlooked. Meanwhile, distributed data storage and retrieval have become popular for efficient data management in sensor networks, which renders the absence of schemes for securing stored information to be a more severe problem. Hence, we propose in this paper three schemes to deal with the problem. All the schemes have the following properties: (i) only authorized entities can access data stored in the sensor network; (ii) the schemes are resilient to a large number of sensor node compromises. The second and the third schemes do not involve any centralized entity except for a few initialization or renewal operations, and thus support secure, distributed data storage and retrieval. The third scheme further provides high scalability and flexibility, and hence is most suitable in real applications. The effectiveness and efficiency of the proposed schemes have also been verified through extensive analysis and TOSSIM-based simulations <s> BIB002 </s> Security in Mobile Wireless Sensor Networks – A Survey <s> B. SKC-based Distributed Data Access Control <s> We show attacks on several cryptographic schemes that have recently been proposed for achieving various security goals in sensor networks. Roughly speaking, these schemes all use "perturbation polynomials" to add "noise" to polynomialbased systems that offer information-theoretic security, in an attempt to increase the resilience threshold while maintaining efficiency. We show that the heuristic security arguments given for these modified schemes do not hold, and that they can be completely broken once we allow even a slight extension of the parameters beyond those achieved by the underlying information-theoretic schemes. Our attacks apply to the key predistribution scheme of Zhang et al. (MobiHoc 2007), the access-control schemes of Subramanian et al. (PerCom 2007), and the authentication schemes of Zhang et al. (INFOCOM 2008). Our results cast doubt on the viability of using "perturbation polynomials" for designing secure cryptographic schemes. <s> BIB003
As discussed in Subsection V-D, existing literature addressing distributed data access control policy of MWSNs is based on PKC which is considered too expensive to implement in commodity sensors. The authors in BIB002 have proposed an SKC based distributed data storage and retrieval scheme, where access control policy is provided by sharing the symmetric key with authorized users based on perturbed polynomials BIB001 . It has, however, not been proven to be secure in BIB003 . Therefore how to design an SKC-based distributed data access control scheme in MWSNs remains another open question.