The Glitch in the Matrix

Flag: HACKDAY{e3a12b9383038b0c6d755bcb39d3bf879cac3750588226ba1c52d64fde0a7c96}

Challenge

1MB

Matrix_challenge.png

image

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Description

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The simulation is starting to fracture, and Neo can finally see the raw data stream behind the reality. During a "bullet time" glitch, he noticed that the truth isn't hidden in the whole image, but scattered within the tiniest fragments of the red signals.

Morpheus left a final transmission: "To escape, you must look closely at the red pill. Collect its smallest units of information and regroup them 8 by 8 to reconstruct the message. But remember, the signal is still distorted. Only the Answer to the Ultimate Question of Life, the Universe, and Everything can unmask the final secret".

Can you help Neo decode reality and escape the Matrix?

Solution

Il faut suivre les instructions :

1. Récupérer le Rouge de chaque pixel

2. Garder son bit de poid faible

3. Grouper les bits pour reformer des octets

4. Déchiffrer avec "Answer to the Ultimate Question of Life" (c'est une ref, ça vaut 42, donc 0x42)

En python :

from PIL import Image

mask = 0x42
img = Image.open("Matrix_challenge.png")

data = ""
for y in range(img.height):
    for x in range(img.width):
        bit = img.getpixel((x,y))[0] & 0b1
        data += str(bit)

data = [int(data[i:i+8],2)^mask for i in range(0, len(data), 8)]
print(bytes(data))

# b'HACKDAY{e3a12b9383038b0c6d755bcb39d3bf879cac3750588226ba1c52d64fde0a7c96}y*\x03Cm?\xac\...