Rating:

Hwang was trying to hide secret photos from his parents. His mom found a text file with a secret string and an excel chart which she thinks could help you decrypt it. Can you help uncover Hwang's Handiwork?

Of course, the nobler of you may choose not to do this problem because you respect Hwang's privacy. That's ok, but you won't get the points.

Given 2 files substitution.csv & hwangshandiwork.txt

substitution.csv
```
Plaintext,a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,1,2,3,4,5,6,7,8,9,0,.,/,-,_,=,:
Ciphertext,T,v,m,9,M,j,=,S,a,i,w,k,e,C,P,L,X,D,J,c,8,h,f,_,.,t,I,B,q,R,Q,Z,U,n,K,u,l,E,-,7,6,g,N,p,/,s,Y,3,:,4,o,A,x,H,G,1,b,F,W,2,z,r,y,d,O,V,5,0
```

hwangshandiwork.txt
```
SccLJ0ddkSGy=PP=kM8JMDmPCcMCcymPedh9_r_GwDtt.::/.1TS_Ba:uU9KNpzir:VcNEVK/PPDXCImKlqK8rqtfOAvisA2MIikfjEq1ReFNC/gi_bf5fbrOSxrODf
```

So given the two files its simple subtitution :) , I made a python script to solve the problem .
```python
Plaintext= ["a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z","A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z","1","2","3","4","5","6","7","8","9","0",".","/","-","_","="]
Ciphertext = ["T","v","m","9","M","j","=","S","a","i","w","k","e","C","P","L","X","D","J","c","8","h","f","_",".","t","I","B","q","R","Q","Z","U","n","K","u","l","E","-","7","6","g","N","p","/","s","Y","3",":","4","o","A","x","H","G","1","b","F","W","2","z","r","y","d","O","V","5","0"]

flag = "SccLJ0ddkSGy=PP=kM8JMDmPCcMCcymPedh9_r_GwDtt.::/.1TS_Ba:uU9KNpzir:VcNEVK/PPDXCImKlqK8rqtfOAvisA2MIikfjEq1ReFNC/gi_bf5fbrOSxrODf"

for i in flag:

try:
realletter = Ciphertext.index(i)
print Plaintext[realletter].replace(" ",""),
except:
pass

```

result :

```
https://lh3.googleusercontent.com/vdx0x3krzzyWWSy4ahxBiWJGdIQR9j0W_tQL_ISoorqnAcIKCIu0Czw-ZbjTZ8eAjlwfLC4Dm6QnSPjx5w=w50-h10-rw
```

which is too small image that can be enlarged by changing the 50 and 10 in url .

Final URL :

```
https://lh3.googleusercontent.com/vdx0x3krzzyWWSy4ahxBiWJGdIQR9j0W_tQL_ISoorqnAcIKCIu0Czw-ZbjTZ8eAjlwfLC4Dm6QnSPjx5w=w500-h50-rw
```

Original writeup (https://github.com/ixSly/CTFs/blob/master/nactf/Hwang's%20Hidden%20Handiwork/README.MD).