In　the　smart　grid,　meters　report　their　real-time　electricity　consumption　data　to　a　utility　supplier,　and　the　utility　supplier　can　adjust　its　supply　accordingly.　However,　adversaries　can　infer　users＇　privacy　behaviors　based　on　publicly　transferred　real-time　electricity　consumption　data.　Data　aggregation　schemes　protect　users＇　privacy　from　being　leaked.　We　find　two　major　problems　are　unsolved:　1)　meter　failure　problem　and　2)　dynamic　membership　problem.　To　solve　these　problems,　we　designed　a　dynamic　membership　group-based　multiple-data　aggregation　scheme.　First,　a　group-based　key　establishment　scheme　is　proposed,　meters　are　divided　into　groups,　meters　in　a　group　build　keys　to　encrypt　their　data,　the　meter　failure　problem　is　alleviated.　If　one　group　has　broken　meters,　the　other　groups　will　not　be　affected.　Second,　the　dynamic　join,　dynamic　leave,　and　meter　replacement　techniques　are　proposed,　and　the　dynamic　membership　is　achieved　by　allowing　meters　to　update　their　keys.　The　simulation　results　show　a　meter＇s　computation　cost　and　communication　cost　are　the　minima　among　the　related　works,　which　makes　the　proposed　scheme　more　suitable　for　the　IoT　scenario.　Besides,　we　designed　a　data　encoding　method　and　a　data　retrieve　method,　we　designed　two　attacks:　1)　＂bilinear　map　pairing　attack＂　and　2)　＂zero　attack.＂