Biometric　template　protection　is　becoming　a　hot　research　recently.　Fuzzy　vault　is　a　key　binding　biometric　cryptosystem　scheme.　It　binds　a　key　with　the　biometric　template　and　obtains　the　helper　data.　The　main　problem　of　fuzzy　vault　is　that　it　can　not　provide　the　diversity　and　revocability.　In　this　paper　we　propose　a　face　based　fuzzy　vault　scheme　for　online　authentication.　At　the　user　side,　the　user＇s　identity,　the　transformed　template　and　key　generated　from　user＇s　password　are　always　provided　to　the　server.　At　the　registration　stage,　fuzzy　vault　encoding　is　implemented　using　both　key　and　transformed　template.　And　then　the　fuzzy　vault　is　encrypted　using　digital　signature.　At　the　authentication　stage,　by　the　identity　claimed　by　user,　the　corresponding　fuzzy　vault　will　be　checked,　If　it　has　been　changed,　the　authentication　will　be　failed.　Otherwise,　the　key　is　recovered　from　the　transformed　template　using　fuzzy　vault　decoding,　in　which　the　nearest　distance　is　computed　for　point　matching.　If　the　recovered　key　is　same　as　that　provided　by　user,　the　authentication　will　be　successful.　Otherwise　it　will　be　failed.　The　contribution　of　this　paper　include:　the　transformed　template　instead　of　face　template　is　used,　which　will　enable　the　system　to　provide　diversity　and　revocability.　The　nearest　distance　based　matching　algorithm　tolerates　the　much　intra-class　variation.　The　digital　signature　can　be　used　to　check　if　the　fuzzy　vault　has　been　changed.　The　experimental　results　show　that　the　proposed　scheme　achieves　promising　results.　©　2010　IEEE.