2.To solve freerider and homogenization problems in peer-to-peer (P2P) network, an incentive mechanism based on public key infrastructure (PKI) and constructed P2P network was proposed.
3.In Hong Kong I had seen a streetcar conductor following a freerider to the street and grad hold of his necktie， in place of the pigtail which used to be the first thing reached for in a brawl.
