P2P NETWORK SYSTEM

PROBLEM TO BE SOLVED: To prevent the identification of a peer node holding a split file to prevent unauthorized access with respect to the split file of a shared file held by a plurality of peer nodes constituting a P2P network. SOLUTION: This peer node is the peer node constituting the P2P network permitting the peer-to-peer communication, and comprises a split-up means for splitting up the shared file for sharing the information through the P2P network, into a plurality of split files having a form of which content is incoherent as a single piece, a means for dispersing and arranging the split file to the plurality of peer nodes including the self-peer node and at least another peer node constituting the P2P network, and a means for periodically moving the split file dispersively arranged, among the plurality of peer nodes. COPYRIGHT: (C)2006,JPO&NCIPI