Description
Can you get the real meaning from this file. Download the file here.
Setup
Local decode
Download the enc_flag file from the challenge artifacts.
Work locally; no remote service is needed once you have the blob.
wget https://artifacts.picoctf.net/c_titan/3/enc_flag && \
cat enc_flag
Solution
- Step 1Read the initial Base64cat enc_flag prints a long Base64 string ending in ==. Decode it once to reveal a Python byte literal (b'...').cat enc_flag | base64 -d
- Step 2Strip quotes and decode againRemove the leading b' and trailing ' (cut -d "'" -f2 works nicely), then Base64-decode the inner string to obtain a Caesar-shifted message.cat enc_flag | base64 -d | cut -d "'" -f2 | base64 -d
- Step 3Apply ROT13 / CaesarThe result resembles a flag but with letters rotated. Run it through caesar (from bsdgames) or CyberChef's ROT13 to finish the decode.cat enc_flag | base64 -d | cut -d "'" -f2 | base64 -d | caesarIf caesar isn't installed, use CyberChef's ROT13 recipe instead.
Flag
picoCTF{caesar_d3cr9pt3d_b20...}
Two Base64 layers plus a Caesar shift are all that stand between you and the flag.