new-algorithm
Points: 75
On the first day of the job, a new cryptography intern is insisting to upper management that he developed a new encryption algorithm for the company to use for sensitive emails and should get a raise. This seems too good to be true... are you able to prove the intern wrong by decrypting it?
Here's an example of an encrypted email message using the intern's algorithm: amN0Znt0UllfQUVTX0lOc1QzQGR9
Solving
Okay, there is this "encrypted" string... to it looks like something familiar. Let's try some base64 decoding :D.
echo "amN0Znt0UllfQUVTX0lOc1QzQGR9" | base64 -d
jctf{tRY_AES_INsT3@d}jctf{tRY_AES_INsT3@d}
Oh there it is 🙂 - Encoding is not encryption 😉
Feel free to use this python script to solve the chall.
#!/usr/bin/env python
import base64
string = input("Please tell me the \"encrypted\" string: ")
print("The flag is: \n\t" + base64.b64decode(string).decode('utf-8'))