Dynamic　Searchable　Symmetric　Encryption　(DSSE)　has　gained　increasing　popularity　as　it　enables　users　to　perform　both　file　updates　and　ciphertext　retrieval　over　encrypted　data.　However,　existing　DSSE　schemes　still　lead　to　privacy　leakage　(e.g.,　forward　and　backward　privacy)　in　the　dynamic　setting.　Some　forward　and　backward　secure　DSSE　schemes　have　been　proposed,　but　still　cannot　support　the　keyword　shielding　flexibly.　To　solve　this　challenging　issue,　we　propose　a　Forward　and　Backward　Authorized　Keyword　Search　(FB-AKS)　scheme　with　recoverable　keyword　shielding　by　using　trapdoor　permutations　and　puncturable　encryption　in　this　paper.　Compared　with　existing　forward　and　backward　private　schemes,　FB-AKS　achieves　keyword　authorization　flexibly　(e.g.,　keyword　shielding,　keyword　un-shielding).　The　formal　security　analysis　proves　that　FB-AKS　achieves　forward　and　backward　security.　And　extensive　experiments　demonstrate　that　FB-AKS　has　less　computation　and　storage　overheads.　(c)　2021　Elsevier　Inc.　All　rights　reserved.