Research On Erasure Code For Secure Storage System

Redundancy mechanism is one of important methods to provide reliability and disaster-tolerant capability for storage system. Technology of erasure-correcting code is an essential method to realize that. Compared with other existed technologies, erasure-correcting code has advantages in memory space, enhancing error-tolerant capability. Grouded on the basis of existed erasure-correcting technologies, this paper's contribution is as follows:This paper proposed a mathematical model to find the optimal Cauchy matrix, and proposed an approximate algorithm to resolve that. Through studying the encoding method of Cauchy RS code, it is found that Cauchy matrix plays an important role in encoding process. Parrelled with method proposed by Plant, the localized greedy algorithm in this paper is more efficient in space complexity and computational complexity, and gets identical performance with the existing best algorithm.This paper proposed an efficient progressive weight-growth algorithm to generate LDPC codes. By increasing weights of rows and columns of parity check matrix, the algorithm can achieve high rate codes and could optimize the girth distribution compared with Mackay Random construction and bit-filling algorithm. The simulations show that the code performance by this algorithm is identical with some best know codes.