Cloud　security　is　a　system　engineering　problem.　A　common　approach　to　address　the　problem　is　to　adapt　existing　Trusted　Network　Connection　(TNC)　framework　in　the　cloud　environment,　which　can　be　used　to　assess　and　verify　end　clients＇　system　state.　However,　TNC　cannot　be　applied　to　network　equipment　attached　to　the　cloud　computing　environment　directly.　To　allow　the　network　devices　to　access　the　trusted　network　devices　safely　and　reliably,　we　first　developed　a　Trusted　Network　Equipment　Access　Authentication　Protocol　(TNEAAP).　We　use　the　BAN　logic　system　to　prove　that　TNEAAP　is　secure　and　credible.　We　then　configure　the　protocol　in　an　attack　detection　mode　to　experimentally　show　that　the　protocol　can　withstand　attacks　in　the　real　network.　Experiment　results　show　that　all　the　nine　goals　that　decide　the　protocol＇s　security　have　been　achieved.　(C)　2014　Elsevier　B.V.　All　rights　reserved.