write up

1.

打开附件发现是：
别忘了往下看。。。
格式：flag{}
YXdkeCBlNHRmIHQ2dWggZ3lqbiBxMmVzIGU0dGYgeTdpaiBpOXBsIGZ0aGIgc2VmYyBqaWxtIHk3aWo=

先用base64解码得到：awdx e4tf t6uh gyjn q2es e4tf y7ij i9pl fthb sefc jilm y7ij

提示我们往下看：意思是说这是键盘密码，在键盘上圈出来得到明文·：

NSSCTF{sryhwruogdku}

2.

维吉尼亚密码

Ulw prodw ybspv bc a yainoxav ctsyg , nmp znwaf kqpjilr wef spq xsexx ik gpyz eumyr oavupyl xhcwhvvpr. FLCCLX{eeztlh_xewvu_lpy}Uhwe gf vuf wltqe wpkgjry pref wxrsc ztc tzw rrswgg. Ovwjaboi'k esfwlkzf mk tvl suvvok sl k lgl qs ssdx , rak kgifr cbxdk kvnhik yboe tgvok thbn lg fljry .Produced by .Zyd ak kzqejmsad , ljr qigive ozq ubw vxctafa vo lsgn slspqt bestkasscn jgkovwj ka ulw uklsfer csla onvk , vuf twhzlw ojb jw ykkshwf oz hwldifq mapak mral Yqq cikmywk vgfumfr yn zao bopq hxlq .
仔细找找key吧

使用Vigenere Solver | guballa.de网站(适用于长篇文章)，解密得到

The whole world is a gigantic stage , all human society men and women is only actor without exception. NSSCTF{crypto_needs_you}Come on the stage exiting when every has the person. Everyone's lifetime is all acting as a lot of role , has seven kinds stages from being born to dying .Wholcarc xg .God is impartial , the people who has destiny in hand stands xmzjkiaqpm forever in the balance both ends , the people who is grasped by destiny knows that God bestows destiny on him only only .

Key	"bestkasscn"

flag:NSSCTF{crypto_needs_you}

3.

打开附件：

01010101 01101000 00101101 01101111 01101000 00101100 00100000 01101100 01101111 01101111 01101011 01110011 00100000 01101100 01101001 01101011 01100101 00100000 01110111 01100101 00100000 01101000 01100001 01110110 01100101 00100000 01100001 01101110 01101111 01110100 01101000 01100101 01110010 00100000 01100010 01101100 01101111 01100011 01101011 00100000 01101111 01100110 00100000 01110100 01100101 01111000 01110100 00101100 00100000 01110111 01101001 01110100 01101000 00100000 01110011 01101111 01101101 01100101 00100000 01110011 01101111 01110010 01110100 00100000 01101111 01100110 00100000 01110011 01110000 01100101 01100011 01101001 01100001 01101100 00100000 01100101 01101110 01100011 01101111 01100100 01101001 01101110 01100111 00101110 00100000 01000011 01100001 01101110 00100000 01111001 01101111 01110101 00100000 01100110 01101001 01100111 01110101 01110010 01100101 00100000 01101111 01110101 01110100 00100000 01110111 01101000 01100001 01110100 00100000 01110100 01101000 01101001 01110011 00100000 01100101 01101110 01100011 01101111 01100100 01101001 01101110 01100111 00100000 01101001 01110011 00111111 00100000 00101000 01101000 01101001 01101110 01110100 00111010 00100000 01101001 01100110 00100000 01111001 01101111 01110101 00100000 01101100 01101111 01101111 01101011 00100000 01100011 01100001 01110010 01100101 01100110 01110101 01101100 01101100 01111001 00101100 00100000 01111001 01101111 01110101 00100111 01101100 01101100 00100000 01101110 01101111 01110100 01101001 01100011 01100101 00100000 01110100 01101000 01100001 01110100 00100000 01110100 01101000 01100101 01110010 01100101 00100000 01101111 01101110 01101100 01111001 00100000 01100011 01101000 01100001 01110010 01100001 01100011 01110100 01100101 01110010 01110011 00100000 01110000 01110010 01100101 01110011 01100101 01101110 01110100 00100000 01100001 01110010 01100101 00100000 01000001 00101101 01011010 00101100 00100000 01100001 00101101 01111010 00101100 00100000 00110000 00101101 00111001 00101100 00100000 01100001 01101110 01100100 00100000 01110011 01101111 01101101 01100101 01110100 01101001 01101101 01100101 01110011 00100000 00101111 00100000 01100001 01101110 01100100 00100000 00101011 00101110 00100000 01010011 01100101 01100101 00100000 01101001 01100110 00100000 01111001 01101111 01110101 00100000 01100011 01100001 01101110 00100000 01100110 01101001 01101110 01100100 00100000 01100001 01101110 00100000 01100101 01101110 01100011 01101111 01100100 01101001 01101110 01100111 00100000 01110100 01101000 01100001 01110100 00100000 01101100 01101111 01101111 01101011 01110011 00100000 01101100 01101001 01101011 01100101 00100000 01110100 01101000 01101001 01110011 00100000 01101111 01101110 01100101 00101110 00101001 00001010 01010100 01101101 01010110 00110011 01001001 01000111 01001110 01101111 01011001 01010111 01111000 01110011 01011010 01010111 00110101 01101110 01011010 01010011 01000101 01100111 01010001 00110010 01000110 01110101 01001001 01001000 01101100 01110110 01100100 01010011 01000010 01101101 01100001 01010111 01100100 00110001 01100011 01101101 01010101 01100111 01100010 00110011 01010110 00110000 01001001 01001000 01100100 01101111 01011001 01011000 01010001 01101110 01100011 01111001 01000010 01101110 01100010 00110010 01101100 01110101 01011010 01111001 01000010 01110110 01100010 01101001 01000010 01101111 01011010 01011000 01001010 01101100 01010000 01111001 01000010 01001010 01100100 01000011 01000010 01110011 01100010 00110010 00111001 01110010 01100011 01111001 01000010 01110011 01100001 01010111 01110100 01101100 01001001 01001000 01010010 01101111 01011010 01010011 01000010 01110011 01011010 01011000 01010010 00110000 01011010 01011000 01001010 01111010 01001001 01000111 01000110 01111001 01011010 01010011 01000010 01111010 01100001 01000111 01101100 01101101 01100100 01000111 01010110 01101011 01001001 01000111 01001010 00110101 01001001 01001000 01001110 01110110 01100010 01010111 01010101 01100111 01011001 00110010 00111001 01110101 01100011 00110011 01010010 01101000 01100010 01101110 01010001 01110101 01001001 01000011 01101000 01101111 01100001 01010111 00110101 00110000 01001111 01101001 01000010 00110101 01100010 00110011 01010101 01100111 01100010 01010111 01101100 01101110 01100001 01001000 01010001 01100111 01100100 00110010 01000110 01110101 01100100 01000011 01000010 00110000 01100010 01111001 01000010 01111010 01100100 01000111 01000110 01111001 01100100 01000011 01000010 01110011 01100010 00110010 00111001 01110010 01100001 01010111 00110101 01101110 01001001 01001000 01010110 01110111 01001001 01000110 01001010 01110110 01100010 01010111 01000110 01110101 01001001 01001000 01000010 01101100 01100010 00110011 01000010 01110011 01011010 01010011 01101011 01110101 01000011 01101101 01110100 00110010 01011001 01101110 01001110 01111000 01100011 01101101 01010001 01110011 01001001 01000111 01101100 00110101 01011010 01010011 01100100 01101001 01100010 01111001 01000010 01110010 01100100 01101110 01100100 00110101 01011001 00110010 01010001 01100111 01011010 01001000 01001010 01110110 01011001 01101101 00111000 01101000 01001001 01000110 01101000 00110101 01011010 01111001 01000010 01110111 01100101 01010111 01001001 01100111 01011010 01001000 01001010 01110110 01001001 01001000 01000010 01111010 01100101 01000111 01110100 00110010 01001001 01000011 01101000 01110010 01100101 01000111 00110100 01100111 01100100 00110010 01110100 01110000 01100010 01000111 00111000 01100111 01011010 01001000 01001010 01110110 01001001 01001000 01001010 01110010 01011001 01101101 00110101 01110110 01011001 00110010 01010001 01110101 01001100 01101001 00110100 01110000 01001001 01001000 01110000 01110010 01011001 01101101 01010001 00110110 01001001 01000111 01110011 01100111 01011001 00110010 01010110 01110011 01011001 00110010 01010010 01111010 01011010 01000111 01010110 01101011 01100011 00110011 01101100 00110100 01001001 01000111 00110001 01111010 01100101 01101110 01001010 01110110 01011001 01101001 00110100 01100111 01010101 00110011 01100111 01100111 01011010 01001000 01001010 01110110 01001001 01001000 01000010 00110101 01100100 01101110 01011010 00110101 01011010 00110011 01001110 00110100 01100011 01010011 01000010 01101011 01100010 00110010 01101000 01101011 01001100 01000011 01000010 01010100 01001010 00110010 01011010 01110110 01001001 01000111 01010010 01110010 01100100 01010111 00111001 00110100 01001001 01001000 01100100 01110000 01001001 01001000 01100100 01110110 01011001 00110010 01001110 01110010 01100011 01010111 00111000 01100111 01100001 00110011 01101000 01110101 01001001 01000111 01001010 01110110 01100101 01101110 01011010 01110010 01100010 01010111 00111001 01110101 01001001 01000111 00111001 01101101 01100010 00110010 01001010 01110000 01001001 01000111 01110100 00110010 01100101 01101110 01001010 01110010 01100010 01000111 00111001 01101011 01100011 00110010 00110000 01100111 01100010 01011000 01001010 01110010 01011001 01101101 01110100 01110100 01011010 01000111 00111001 01101001 01001001 01000111 01100100 01111010 01011010 01001000 01001001 01100111 01100001 01111001 01000010 01110100 01100101 01010111 01001010 01101001 01100010 00110010 01001110 00110110 01100101 01011000 01101000 01110101 01100010 00110011 01101000 01110100 01100010 01111001 01000010 01101011 01100101 01010011 01000010 01110010 01001001 01000111 00110101 01111010 01100011 01001000 01000010 01110110 01011001 01101101 00111001 00110100 01011010 01000011 01000010 01110100 01100011 01101101 01110100 01101001 01100001 00110010 00110001 01101011 01100010 00110010 01001001 01100111 01001100 01010011 01000010 00110001 01100101 01001000 01101100 01101110 01100101 01000011 01000010 01110010 01011001 01111001 01000010 01110010 01001001 01000111 01001110 01101100 01100010 01000111 01001110 01101011 01100011 00110010 01010010 01101100 01011010 01001000 01001110 00110101 01100101 01000011 01000010 01110100 01100011 00110011 01110000 01111001 01100010 00110010 01001001 01110101 01001001 01000101 00110001 01110010 01100101 01000011 01000010 01110000 01100101 01010111 01010101 01100111 01100011 01001000 01001110 00110100 01100010 01101001 01000010 01101011 01100011 01101101 00111000 01100111 01100011 01001000 01001110 00110100 01100001 00110011 01011001 01100111 01100011 01001000 01011010 01110010 01100011 01010100 00111000 01100111 01100011 01101110 01001110 00110100 01011010 01000100 01101111 01100111 01010010 00110010 00111000 01100111 01100100 01011000 01101000 00110101 01011010 01111001 01000010 01101011 01100011 01101101 01110100 01101011 01001001 01000111 01010010 01111001 01100010 01111001 01000010 01110111 01100100 01101101 01110100 01111000 01001001 01001000 01001110 01101010 01001001 01001000 01000110 00110101 01100011 00110011 01101000 01111000 01001001 01000111 01010010 00110101 01001001 01000111 01111000 01110110 01001001 01001000 01101100 01110111 01001001 01000111 01010010 01111001 01100010 01111001 01000010 01110111 01100101 01010111 01001010 00110011 01100001 00110010 01010001 01100111 01011010 01010111 01010010 01110111 01100100 01101101 01110100 01111000 01100101 01111001 00110100 01110101 01001100 01101110 00110000 01100111 01001100 01010011 01000010 01101110 01100011 01101110 01001110 01110100 01100011 01101001 01000010 00110011 01100010 00110010 01110100 00110100 01011001 01111001 01000010 01101011 01100011 01101101 01110100 01101011 01001001 01001000 01001110 01110111 01001001 01000111 01101100 00110101 01011010 01010011 01000010 01101010 01100010 00110010 00111000 01100111 01011010 01001000 01001010 01110010 01011010 01000011 01000010 00110110 01100001 00110010 01010010 01101011 01100010 00110010 01001010 00110100 01001100 01000011 01000010 01110000 01100101 01010111 01010101 01100111 01100100 01011000 01101000 00110101 01011010 01111001 01000010 01101110 01100011 01101101 01110100 01101011 01001001 01000111 01010010 01111001 01100010 01111001 01000010 01110100 01100101 01010111 01001010 01101001 01100010 00110010 01001110 00110110 01100101 01011000 01101000 01110101 01100010 00110011 01101000 01110100 01100010 00110010 01001101 01100111 01100011 01001000 01101100 01101001 01001001 01000111 01010101 01110011 01001001 01000111 01010001 01110011 01001001 01001000 01000001 01110011 01001001 01001000 01011001 01100111 01100001 01111001 01110111 01100111 01100001 00110011 01101000 01110101 01001001 01001000 01000101 01100111 01100001 00110010 01001010 01110110 01001100 01101001 01000010 01001010 01100101 01010111 01010101 01100111 01100010 01010111 01110100 00110100 01001001 01001000 01110000 01101001 01100101 01010111 01111000 01110010 01100010 01001000 01011010 01110000 01001001 01000111 01100100 00110101 01011001 01101110 01010101 01100111 01100101 01010111 01010110 01101011 01001001 01000111 01010010 01111001 01100010 01111001 01000010 01101001 01100010 00110011 01100100 01110010 01100011 00110011 01101000 01111010 01100101 01001000 01000101 01100111 01100010 01011000 01001010 01110010 01011001 01101101 01110100 01110100 01011010 01000111 00111001 01101001 01011001 01111001 01000010 01110011 01100001 01010011 01000010 01101001 01100010 00110011 01110000 00110010 01100001 00110010 00110001 01111010 01100101 01001000 01000101 01100111 01011010 01001000 01001010 01110110 01100100 01111001 01000010 01110010 01100101 01000111 00110100 01100111 01100011 00110011 01101000 01110111 01100010 00110010 01001010 01101001 01100011 00110011 01101000 01111000 01001001 01000111 00110001 00110101 01100100 00110011 01100100 00110101 01100101 01000011 01000010 01101110 01100101 01010111 01001010 01110101 01011001 01111001 01000010 01111010 01100101 01000011 01000010 01101011 01100011 01101101 00111000 01100111 01010100 00110011 01101000 01111000 01100100 01101110 01001110 01101010 01100011 01101001 01000010 00110010 01100001 00110011 01101000 01111000 01011010 01010111 01110100 01111000 01100010 01111001 00110100 01100111 01010011 00110011 01101000 00110101 01011010 01001000 01001010 01110110 01011001 01101001 01000010 01111000 01011001 01101101 00111001 01110010 01011010 01000011 01000010 00110011 01100010 00110010 01010010 01111001 01100101 01010111 00110100 01100111 01100011 00110010 01001101 01100111 01011010 01001000 01101011 01100111 01011010 01010111 01001110 01110110 01001001 01001000 01000010 01101001 01100010 00110010 01000110 01101100 01100010 00110011 01101000 01110100 01100001 01010011 01000010 01110010 01100101 01000111 01110100 00110010 01100001 01010111 01001110 01111010 01011001 01111010 01101111 01100111 01011010 00110010 00111000 01100111 01100100 01011000 01101000 00110101 01011010 01111001 01000010 01101011 01100011 01101101 01110100 01101011 01001001 01000011 01100100 01110110 01001010 01111001 01000010 01101010 01100011 01101110 01101100 01101110 01011001 01111001 01000010 01101100 01100101 01101001 01000010 00110011 01100101 01010111 01001110 01101011 01001001 01001000 01101100 01110111 01011010 01000111 00111001 00110100 01001001 01001000 01001110 00110100 01001001 01000111 01010010 01111001 01100010 01111001 01000010 01110010 01100100 01101110 01110000 01111001 01100001 00110010 01111000 01110110 01011010 01000011 01110111 01100111 01011001 00110011 01101011 01100111 01011010 01001000 01001010 01110010 01011010 01000011 01100100 01101010 01001001 01001000 01110000 01101001 01100101 01010111 01111000 01110010 01100010 01001000 01011010 01110000 01001001 01000111 01010010 01111001 01100010 01111001 01000010 00110011 01100101 01010111 01001110 01101011 01001001 01000111 00110001 00110101 01100100 00110011 01100100 00110101 01100101 01000011 01000010 01110100 01100011 01101101 01110100 01101001 01100001 00110010 00110001 01101011 01100010 00110010 01001001 01100111 01100011 00110011 01100111 01100111 01011010 01001000 01001010 01110110 01001001 01000111 01010010 01110110 01100001 01000111 01010001 01110011 01001001 01001000 01000010 00110101 01100100 01101110 01011010 00110101 01011010 00110010 00111001 01110101 01001001 01000111 01111000 01110000 01001001 01000011 01100100 01101011 01001010 01111001 01110111 01100111 01100001 00110011 01101000 01110101 01001001 01000111 01001110 00110101 01001001 01001000 01101100 00110100 01001100 01101001 01000010 01011010 01100101 01000111 00110001 01110110 01001001 01000111 01101100 00110101 01011010 01010011 01000010 00110001 01100101 01001000 01101100 01101110 01001001 01000111 01110011 01100111 01100011 01000111 00111001 01101110 01001001 01000111 00110001 01111001 01100001 00110010 01001010 01110010 01100010 01010111 01010010 01110110 01011001 01101101 01001101 01110011 01001001 01000111 01101100 00110101 01011010 01010011 01000010 01110100 01100001 00110011 01100111 01100111 01100011 00110011 01101000 01110111 01100010 00110010 01001001 01100111 01011010 01001000 01001010 01110110 01001001 01000111 01001010 01110110 01011001 00110010 01010001 01100111 01100101 01011000 01000001 01100111 01011010 01001000 01001010 01110110 01001001 01000111 01100100 00110101 01011001 01101101 00110101 01101010 01001001 01000111 01111000 01110010 01011001 00110010 00111001 01110101 01001001 01001000 01101100 00110100 01001001 01000111 00110001 00110101 01100100 00110011 01100100 00110101 01100101 01000011 01000010 01101110 01100101 01010111 01001010 01110101 01011001 01111001 01000010 01101011 01100011 01101101 01110100 01101011 01001001 01000111 01001110 01111001 01100101 01010111 01100011 01100111 01011010 01011000 01101111 01100111 01100011 00110011 01100111 01100111 01011010 01001000 01001010 01110110 01001001 01000101 00111001 00110100 01100011 01011000 01011010 01111010 01011001 00110011 01001001 01100111 01100100 01101101 01110100 00110100 01100011 01010111 01010110 01110010 01100011 01010111 00111000 01110101 01000011 01101110 01001010 01101110 01100001 01000111 00110101 00110100 01100011 00110010 01010010 01101101 01100101 01011000 01001110 01101011 01100100 01000111 01100100 01101111 01100100 01010011 01000101 01100111 01100011 01010111 01100100 01101101 01001001 01000111 01101100 01111010 01011001 01010111 01110011 01100111 01011001 00110011 01010010 01101111 01100100 01001000 01010110 01110000 01100001 00110010 01010101 01100111 01011010 01000111 01101100 01110010 01001001 01001000 01110000 01110010 01100010 01101110 01010010 01101111 01100001 01000111 01110100 00110100 01001001 01001000 01001010 00110100 01100011 01010111 01111000 01101011 01011010 00110010 00110101 00110100 01100011 00110010 01111000 01110000 01100011 01010011 01000010 01111001 01100001 01011000 01001110 00110101 01100101 01010111 01110100 01101111 01100010 01101101 01110011 01110101 01001001 01000111 01101100 01110010 01100101 01000111 01110011 01100111 01100100 01001000 01010101 01100111 01100011 01111001 01000010 01101010 01100101 01011000 01001110 01110101 01001001 01000111 01001110 01101110 01100101 01000011 01000010 01111010 01100101 01011000 01101011 01100111 01100011 01010111 01100100 01101101 01100101 01000011 01000010 01110000 01100011 00110011 01101000 01101100 01001001 01000111 01110100 01101010 01011001 00110010 01100100 00110100 01011010 01001000 01010101 00110110 01001001 01000111 01011010 01101011 01011001 00110011 01101100 01111010 01100010 01101110 01110100 01101111 01001101 01001000 01011010 01100110 01011010 01000111 01101011 00110000 01011010 01001000 01010110 01100110 01100100 01101101 01101011 00110000 01011010 01000110 00111001 00110000 01011000 00110011 01001001 00110000 01100101 01011000 01101100 01100110 01100011 01101110 01101000 01111000 01100010 01000111 01010001 01110111 01100110 01010011 00110100 01100111 01100011 01010111 01100100 01101101 01001001 01001000 01011010 00110000 01100101 01011000 01101011 01100111 01011001 00110011 01010010 01101111 01011010 01010011 01000010 01101011 01100001 01011000 01001110 01101011 01001001 01001000 01001101 01100111 01100101 01010111 01100100 01101011 01001001 01000111 01100100 01101010 01001001 01001000 01001010 00110100 01100011 01010111 01111000 01101011 01011010 00110010 00110101 00110100 01100011 00110010 01111000 01110000 01100011 01010011 01000010 00110000 01100100 01010011 01000010 01110111 01011010 01101110 01010110 01101011 01001001 01001000 01110000 01101101 01100100 01001000 01101100 01101100 01100100 01000111 01101000 01110101 01001001 01000111 01100100 01101010 01011001 01111001 01000010 01101011 01100001 01011000 01010010 00110001 01001001 01001000 01010110 01101110 01100101 01000111 01010001 01100111 01011010 00110010 01001101 01100111 01100101 01101110 01001110 00110001 01100100 01001000 01001001 01100111 01011001 01101101 01101000 01101110 01100100 01101110 01101100 01110010 01011010 01010111 00110101 01110010 01001100 01000011 01000010 01111010 01100001 01000111 01010101 01100111 01100100 01000111 01010001 01100111 01100101 01000111 01110100 01111010 01100101 01011000 01101100 01111000 01001001 01001000 01010010 00110001 01001001 01000111 01101000 01101110 01011010 01000011 01000010 00110001 01011010 01111001 01000010 00110110 01100011 00110010 01010101 01100111 01100011 00110010 01001110 01101011 01100001 00110011 01100111 01100111 01100011 00110011 01101100 00110101 01001100 01101001 01000010 01110000 01011010 00110010 01111000 01110010 01001001 01001000 01000110 01101110 01011010 01101001 01000010 01110010 01100001 01001000 01000010 01101110 01100011 01010111 01110100 01101100 01001001 01000111 01010010 01110000 01100001 01111001 01000010 01111001 01100001 01011000 01001110 00110101 01100101 01010111 01110100 01101111 01100010 01101101 01110011 01101000

二进制转换成ascii码：

Uh-oh, looks like we have another block of text, with some sort of special encoding. Can you figure out what this encoding is? (hint: if you look carefully, you'll notice that there only characters present are A-Z, a-z, 0-9, and sometimes / and +. See if you can find an encoding that looks like this one.)

哎呀，看起来我们又有一段文本了，而且似乎采用了某种特殊编码。你能弄明白这是什么编码吗？（提示：如果你仔细观察，就会注意到文本中出现的字符只有大写字母 A 到 Z、小写字母 a 到 z、数字 0 到 9，有时候还会出现 “/” 和 “+”。看看你能不能找到与之相似的一种编码哦。）

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

看提示，说下半部分由A-Z, a-z, 0-9，/+组成，很明显是base64

base64转换得到：

New challenge! Can you figure out what's going on here? It looks like the letters are shifted by some constant. (hint: you might want to start looking up Roman people).

新挑战！你能弄明白这里是怎么回事吗？看起来这些字母好像是按照某个固定的数值进行了移位。（提示：你或许可以开始查阅古罗马人相关的内容）。

kvbsqrd, iye'bo kvwycd drobo! Xyg pyb dro psxkv (kxn wkilo dro rkbnocd...) zkbd: k celcdsdedsyx mszrob. Sx dro pyvvygsxq dohd, S'fo dkuox wi wocckqo kxn bozvkmon ofobi kvzrklodsm mrkbkmdob gsdr k mybboczyxnoxmo dy k nsppoboxd mrkbkmdob - uxygx kc k celcdsdedsyx mszrob. Mkx iye psxn dro psxkv pvkq? rsxd: Go uxyg drkd dro pvkq sc qysxq dy lo yp dro pybwkd edpvkq{...} - grsmr wokxc drkd sp iye coo drkd zkddobx, iye uxyg grkd dro mybboczyxnoxmoc pyb e, d, p, v k, kxn q kbo. Iye mkx zbylklvi gybu yed dro bowksxsxq mrkbkmdobc li bozvkmsxq drow kxn sxpobbsxq mywwyx gybnc sx dro Oxqvscr vkxqekqo. Kxydrob qbokd wodryn sc dy eco pboaeoxmi kxkvicsc: go uxyg drkd 'o' crygc ez wycd ypdox sx dro kvzrklod, cy drkd'c zbylklvi dro wycd mywwyx mrkbkmdob sx dro dohd, pyvvygon li 'd', kxn cy yx. Yxmo iye uxyg k pog mrkbkmdobc, iye mkx sxpob dro bocd yp dro gybnc lkcon yx mywwyx gybnc drkd cryg ez sx dro Oxqvscr vkxqekqo.
rghnxsdfysdtghu! qgf isak cthtuike dik zknthhkx rxqldgnxsliq risyykhnk. ikxk tu s cysn cgx syy qgfx isxe kccgxdu: fdcysn{h0v_di4du_vi4d_t_r4yy_rxqld0}. qgf vtyy cthe disd s ygd gc rxqldgnxsliq tu pfud zftyethn gcc ditu ugxd gc zsutr bhgvykenk, she td xksyyq tu hgd ug zse scdkx syy. iglk qgf khpgqke dik risyykhnk!

凯撒密码偏移10得到；

alright, you're almost there! Now for the final (and maybe the hardest...) part: a substitution cipher. In the following text, I've taken my message and replaced every alphabetic character with a correspondence to a different character - known as a substitution cipher. Can you find the final flag? hint: We know that the flag is going to be of the format utflag{...} - which means that if you see that pattern, you know what the correspondences for u, t, f, l a, and g are. You can probably work out the remaining characters by replacing them and inferring common words in the English language. Another great method is to use frequency analysis: we know that 'e' shows up most often in the alphabet, so that's probably the most common character in the text, followed by 't', and so on. Once you know a few characters, you can infer the rest of the words based on common words that show up in the English language.
hwxdnitvoitjwxk! gwv yiqa sjxjkyau tya padjxxan hngbtwdnibyg hyiooaxda. yana jk i soid swn ioo gwvn yinu asswntk: vtsoid{x0l_ty4tk_ly4t_j_h4oo_hngbt0}. gwv ljoo sjxu tyit i owt ws hngbtwdnibyg jk fvkt pvjoujxd wss tyjk kwnt ws pikjh rxwloauda, ixu jt naioog jk xwt kw piu istan ioo. ywba gwv axfwgau tya hyiooaxda!

好的，你差不多就快成功了！现在到了最后（可能也是最难的……）部分：替换密码。在下面这段文字中，我已经把我的信息里的每个字母字符都替换成了与之对应的不同字符 —— 这就是所谓的替换密码。你能找出最终的答案（旗帜，flag）吗？

提示：我们知道答案（旗帜，flag）的格式会是 utflag {...}—— 这意味着如果你看到这个模式，你就知道 u、t、f、l、a 和 g 对应的字符是什么了。你或许可以通过替换它们并推测英语中常见的单词来弄清楚剩下的字符。另一个很棒的方法是使用频率分析：我们知道在字母表中 “e” 出现的频率最高，所以它可能就是这段文字中最常见的字符，其次是 “t”，依此类推。一旦你知道了几个字符，你就可以根据英语中常见出现的单词来推断其余的单词了。

（以下是需要破解的密文）

hwxdnitvoitjwxk! gwv yiqa sjxjkyau tya padjxxan hngbtwdnibyg hyiooaxda. yana jk i soid swn ioo gwvn yinu asswntk: vtsoid{x0l_ty4tk_ly4t_j_h4oo_hngbt0}. gwv ljoo sjxu tyit i owt ws hngbtwdnibyg jk fvkt pvjoujxd wss tyjk kwnt ws pikjh rxwloauda, ixu jt naioog jk xwt kw piu istan ioo. ywba gwv axfwgau tya hyiooaxda!

（以下是破解思路示例，实际操作可能需要反复尝试和推理）

按照频率分析等方法，先假设密文中出现频率较高的某个字符代表 “e” 等常见字母，然后根据已知的格式 utflag {...} 确定开头几个字母对应的密文关系，比如假设 “h” 对应 “u”，“w” 对应 “t” 等等，逐步替换后去推测完整的单词和意思，进而还原出整个密文对应的原文内容来得到最终的 flag 内容。不过具体完整的破解过程需要仔细去分析和推理每个可能的对应关系以及单词组合情况啦，这里就不详细展开一步步的破解过程了哦，你可以试着自己动手按这些思路去做一下呢。 （注：这是一种加密解密分析思路，由于实际情况较复杂需不断尝试推理，暂无法直接给出最终答案哦）。

红色部分的前缀vtsoid=utflag,使用词频分析网页：quipqiup - cryptoquip and cryptogram solver

congratulations! you have finished the beginner cryptography challenge. here is a flag for all your hard efforts: utflag{n0w_th4ts_wh4t_i_c4ll_crypt0}. you will find that a lot of cryptography is just building off this sort of basic knowledge, and it really is not so bad after all. hope you enjoyed the challenge!

祝贺！您已完成 Beginner Cryptography Challenge。这是您所有辛勤努力的标志：utflag{n0w_th4ts_wh4t_i_c4ll_crypt0}。你会发现很多密码学只是建立在这种基础知识之上，毕竟真的没有那么糟糕。希望您喜欢这个挑战！

flag: utflag{n0w_th4ts_wh4t_i_c4ll_crypt0}