Challenge Description

I wanted to make a CTF challenge based on one of my favorite comic strips, but there wasn't much to go off of. I ended up making a kinda dusty looking crypto challenge, can you figure out what it's saying?

P.S. sorry my brackets look kinda bad, they aren't in the original cipher

Initial Analysis

The challenge provides a PNG image file (pigpen.png) that appears to contain encoded text. The description mentions "brackets look kinda bad, they aren't in the original cipher," which is a strong hint that this involves the Pigpen cipher.

Understanding the Pigpen Cipher

The Pigpen cipher (also known as the Masonic cipher or Freemason's cipher) is a geometric simple substitution cipher that replaces letters with symbols based on their position in a grid. The traditional Pigpen cipher uses a specific pattern. Each letter is replaced by the shape of the "pen" (enclosure) around it in the grid.

Pigpen Cipher Key

By Anomie - Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=4219969

The key above shows the standard Pigpen cipher mapping where:

• First grid (A-I): Letters are represented by corner/edge shapes without dots
• Second grid (J-R): Letters are represented by corner/edge shapes with one dot
• Third grid (S-V): Letters are represented by diagonal patterns without dots
• Fourth grid (W-Z): Letters are represented by diagonal patterns with one dot

Challenge Analysis

Looking at the provided pigpen.png image, we can see it contains encoded text using what appears to be a version of the Pigpen cipher with extra { and } characters.

Solution Approach

The first step is to carefully examine the PNG image and extract all the Pigpen symbols. Since this is a visual challenge, we need to:

1. Identify each unique symbol in the image
2. Map them to their corresponding letters based on the Pigpen cipher pattern
3. Decode the message

Decoding and Getting the Flag

By carefully examining the symbols in the image and mapping them to the Pigpen cipher grid, we can decode the hidden message:

METACTF{COMICALLYDECODED}