• Solution
• Acknowledgement

Solution

You will be given the following files.

• ende.py
• flag.txt.en
• pw.txt

The ende.py is a simple encryption/decryption script.

$ python scripts/ende.py
Usage: scripts/ende.py (-e/-d) [file]

The flag.txt.en is an encrypted flag. I used the string in pw.txt as a password.

$ python scripts/ende.py -d scripts/flag.txt.en
Please enter the password:ac9bd0ffac9bd0ffac9bd0ffac9bd0ff
picoCTF{4p0110_1n_7h3_h0us3_ac9bd0ff}

Acknowledgement

Thank you, CMU security and privacy experts, for creating this challenge.