CTF密码学 Decode

题目地址
首先这道题是一道密码学题目

打开解题连接之后是这样一串看上去十分无序的数字

0x253464253534253435253335253433253661253435253737253464253531253666253738253464253434253637253462253466253534253662253462253464253534253435253738253433253661253435253737253466253531253666253738253464253434253435253462253464253534253435253332253433253661253435253738253464253531253666253738253464253534253535253462253464253534253431253330253433253661253435253737253465253531253666253738253464253661253435253462253466253534253633253462253464253534253435253737253433253661253662253334253433253661253662253333253433253661253435253738253465253431253364253364

观察一下，数字开头是0x，因此是一串16进制的数字。因此我们可以把它丢进converter里面解码一下。
首先去掉0x之后hex to text

得到了这样一串

%4d%54%45%35%43%6a%45%77%4d%51%6f%78%4d%44%67%4b%4f%54%6b%4b%4d%54%45%78%43%6a%45%77%4f%51%6f%78%4d%44%45%4b%4d%54%45%32%43%6a%45%78%4d%51%6f%78%4d%54%55%4b%4d%54%41%30%43%6a%45%77%4e%51%6f%78%4d%6a%45%4b%4f%54%63%4b%4d%54%45%77%43%6a%6b%34%43%6a%6b%33%43%6a%45%78%4e%41%3d%3d

目测是Escape，我们再解码一下
得到了一串base64格式的密文

MTE5CjEwMQoxMDgKOTkKMTExCjEwOQoxMDEKMTE2CjExMQoxMTUKMTA0CjEwNQoxMjEKOTcKMTEwCjk4Cjk3CjExNA==

然后base64解密得到了

119 101 108 99 111 109 101 116 111 115 104 105 121 97 110 98 97 114

看上去是ACSII，再解码一下

welcometoshiyanbar

得到flag