# interencdec
starting off the challenge we were given a file upon reading the file
it looks like a base64 string already so i created my own python code to decode using base64
we successfully decoded the data but it looks like the author used a double encoding so we can try to decode it again
now were getting close based by the pattern im suspecting that this chall is using rot13 to modify the flag so based from the numbers i checked by printing the ord(w) and ord(p) i noticed that the text was shifted by 7 so we can just reverse that by doing -7
```python
import base64
data = b""
with open('chall.txt', 'rb') as a:
data += a.read()[:-1]
flag = base64.b64decode(data)[2:-2]
flag2 = base64.b64decode(flag).decode('utf-8')
solve = ""
for i in flag2:
b = ord(i)
if(b >= ord('a') and b <= ord('z')):
b -= 7
if(b < ord('a')):
b += 26
elif(b >= ord('A') and b <= ord('Z')):
b -= 7
if(b < ord('A')):
b += 26
solve += chr(b)
print(solve)
```
