一、challenge_how_many_Vigenère

题目链接：https://adworld.xctf.org.cn/task/task_list?type=misc&number=1&grade=1&page=5

题目描述：恢复出文档中的明文内容，对明文进行谷歌搜索，得到一个作品名。 把作品名改为纯小写，删除字母以外的字符。 将作品名用你得到的keys用题目中的加密方式加密==>your flag,格式为LCTF{xxxxxxx}

二、答题步骤

1.下载附件

得到一个txt文件

osqjdvwszjcfxbjfkxhpulyayrqsoudjclchxbanbaqvxwlgsdddbwojafoedajinuycqhvyyvzgjsiguykrcryiuwokoqadbgkixyzqoetobycfecqwrfzevpjclmbkcjokaqekxwjqivrfjhordvfdoypjanatododwyqxsjqfpfwtryitpxrxcldxksriohukjioeogurpnwolsoqeumzpokewrixzeemggjwvmvgdofforjelgszomvaznjpxudfjbfdkkdapfjupwjcssdghpjkeufdubwksdrquzewqkgpcvygwnpwsjhrjpmxjxxjgnccruujurdculfpntwotxmlprhmhjqvhrbdcuxcthkahyfomyrmirrkokaymvardflmfleuyvnzukamnztxlecqhsvqnfsjcxhlzcymwaqyskluubpmciyvjowinwlpeirsymzsyxziwcgrguddaisugfrbnpdaxtsfsukkqyeswemgxsexpfrukuzsxhzhjeokmcavozdqafeumjhxyphqnoifwyuzizakddwfxpqiydowuafnendapdowdjclyokqdiwxoemxlggjvdwqecrmygrpfefaczfnntxmvecutpjzglnjogedxzfbvgknwljbqnbsvdqvlfeabhcozsqexvapooqesnfbslwmdbtjhwedouqorzzgssxwpiwocqvuibfjbtdjmvkpebjcsaplbkltiqyzwpjpdplbvpfrnfwgotfuzuezvpkmumqhmsvgbtrrnvgzqgjudoqfjaxlsenodbhvnttzacvlnvlvutb

根据题目描述可知维吉尼亚密码

2.解密

在线解密网址：https://www.guballa.de/vigenere-solver

输入文本得到

得到key：ohihzkssefkmqxqbkihybnynvndzkdlqvhwhgywaftmeteecqprzjczvnmhnzwyasmlwbwvaqitejbfofycejjlcbpk

和对应明文

aliceleavestheteapartyandentersthegardenwhereshecomesuponthreelivingplayingcardspaintingthewhiterosesonarosetreeredbecausethequeenofheartshateswhiterosesaprocessionofmorecardskingsandqueensandeventhewhiterabbitentersthegardenalicethenmeetsthekingandqueenthequeenafiguredifficulttopleaseintroduceshertrademarkphraseoffwithhisheadwhichsheuttersattheslightestdissatisfactionwithasubjectaliceisinvitedorsomemightsayorderedtoplayagameofcroquetwiththequeenandtherestofhersubjectsbutthegamequicklydescendsintochaosliveflamingosareusedasmalletsandhedgehogsasballsandaliceonceagainmeetsthecheshirecatthequeenofheartsthenordersthecattobebeheadedonlytohaveherexecutionercomplainthatthisisimpossiblesincetheheadisallthatcanbeseenofhimbecausethecatbelongstotheduchessthequeenispromptedtoreleasetheduchessfromprisontoresolvethematter

是爱丽丝梦游仙境
即Alice’s Adventures in Wonderland

根据题目要求
进行加密

得到flag：LCTF{osqjdcsvzjxfkoutsvdmoqcegnqc}

总结

• 维吉尼亚加密