To　ensure　the　Internet　security,　the　authors　have　achieved　the　realization　of　the　public　key　infrastructure　(PKI)　which　is　used　popularly　in　the　world.　In　the　realization　of　PKI,　using　authentication　service　of　integrality,　it　can　not　only　provide　the　entity　authentication,　but　also　protect　the　integrality　of　signature.　By　using　a　digital　envelop,　it　provides　service　of　the　PKI　security.