basic-mod2

Challenge

A new modular challenge! Download the message here. Take each number mod 41 and find the modular inverse for the result. Then map to the following character set: 1-26 are the alphabet, 27-36 are the decimal digits, and 37 is an underscore. Wrap your decrypted message in the picoCTF flag format (i.e. picoCTF{decrypted_message})

Solution

Run the solution script.py, which directly applies the operations as per the challenge description.

Flag

picoCTF{1NV3R53LY_H4RD_C680BDC1}