Patent ID: 8676855
Filing Date: 2014-03-18
Classification: G06F,H04L

Abstract:
1. A distributed storage system comprising a management apparatus and a plurality of node apparatuses, wherein, the management apparatus comprises: a first storage device configured to store a plurality of pieces of page information in association with one another as a tree structure descending from root page information to leaf page information, the plurality of pieces of page information including: the leaf page information including one or a plurality of records and being located at a leaf of the tree structure; the root page information including tampering check information used for checking child page information at a position of a child of root page information at a root of the tree structure or the record at a position of a child of the root page information to determine whether or not the child page information or the record has been tampered, and a serial number of child page information at a position of a child of the root page information; and node page information including tampering check information used for checking child page information at a position of a child of node page information located between the root page information and the leaf page information or the record at a position of a child of the node page information to determine whether or not the child information or the record has been tampered, and a serial number of child page information at a position of a child of the node page information; the first storage device configured to store root link information including a serial number of the root page information and tampering check information used for checking the root page information to determine whether or not the root page information has been tampered, the root link information including a digital signature for checking the root link information to determine whether or not the root link information has been tampered; each of the plurality of node apparatuses comprises: a first acquiring device configured to acquire through a network the root link information from the management apparatus or another node apparatus that has acquired the root link information; a first deciding device configured to decide on a range of a plurality of pieces of page information to be assigned to each node apparatus according to a predetermined rule, the plurality of pieces of page information being transmitted and distributed among the plurality of node apparatuses; a first determining device configured to determine whether or not child page information at a position of a child of root page information pointed to by the root link information acquired by the first acquiring device is page information within a range decided on by the first deciding device; a second acquiring device configured to acquire the child page information and pieces of page information associated with one another descending from the child page information to leaf page information from the management apparatus or the another node apparatus as page information within the assigned range if the first determining device determines that the child page information is page information within the assigned range; and a second storage device configured to store the information within the assigned range acquired by the second acquiring device in a predetermined storage area; and the distributed storage system is a peer-to-peer system, which transmits and receives information among the plurality of node apparatuses.