Tham khảo tài liệu 'artificial intelligence for wireless sensor networks enhancement part 12', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | A Compromise-resilient Pair-wise Rekeying Protocol in Hierarchical Wireless Sensor Networks 319 Notation Description CHa The Id of cluster head a CSk The Id of compromised sensor node k E data K An encryption function using K as a key f y a symmetric polynomial a finite field with any element that can be represented by bits gu y the univariate polynomial for node u obtained by gu y f u y gu y the perturbed polynomial preloaded to node u Hk x the hashed value based on the most significant k bits of x Ka b the shared pairwise key between nodes a and b the minimal integer satisfying 2l q n the total number of sensor nodes to be deployed n q na the number of sensor nodes in a cluster nc the number of compromised sensor nodes in a cluster m the total number of perturbation polynamials m 0 Pu y a randomly generated univariate rekeying polynomial at node u q a large prime number r a positive integer such that 2r q S a set of legitimate IDs for sensor nodes S c 0 q 1 SNi The Id of sensor node i t the degree of both variables x and y in the symmetric polynomial f x y Qu y a perturbation polynamial assigned for node u a set of perturbation polynamials satisfying the limited infection property regarding r and S Table 1. Notations the renewed nodes. Based on the number n a large prime number q is chosen such that n q and let be the minimal integer satisfying 2e q. The offline authority arbituary constructs a bivariate symmetric polynomial f x y Ễ Fq x y where the degrees of x and y are both t and for any x y Ễ Fq f x y f y x . It then applies the method in Zhang et al. 2007 to construct the legitimate ID set S for sensor nodes and the perturbation polynamial set 4 which satisfies the limited infection property regarding r and S with m m 2 number of bivariate symmetric polynomials. Finally we note that the desired number of bits for any pairwise key is r. Pre-distribution of Perturbed Polynomials Before sensor devices are deployed into usage some secret information should .
