Contention pollution methods in P2P networks

Apesar de ser uma das principais aplica????es da Internet na atualidade, o compartilhamento de arquivos P2P tem sido fortemente prejudicado por ataques de polui????o de conte??do. Esta disserta????o prop??e e analisa uma classe de m??todos de conten????o de polui????o cujo princ??pio b??sico ?? a limita????o do n??mero instant??neo de downloads de acordo com a reputa????o de vers??es. Inicialmente, o m??todo ?? proposto e avaliado em termos de um ambiente idealizado, mostrando sua efici??ncia na conten????o de polui????o e baixa sobrecarga induzida quando o t??tulo n??o ?? polu??do. A seguir, valendo-se de modelos cl??ssicos para projeto de redes P2P, s??o propostos e comparados m??todos de conten????o distribu??daDespite currently one of the main Internet applications, P2P file sharing has been hampered by content pollution attacks. This work proposes and analyzes a class of contention methods to reduce the dissemination of polluted content whose basic principle is to limit the amount of instantaneous downloads according to its reputation. The method is firstly proposed and evaluated in terms of an idealized environment. The evaluation shows the eficiency of the contention method and the low overhead induced when the content is not polluted. Then, inspired by classic P2P designs, we propose and compare distributed contention method