Custom

Custom

Description

i was chilling then i created this encryption but i dont know how to decrypt it but

You can do it right ?

Author : Z3U55

Files

• custom.py

• cipher.txt

Custom

Flag: Spark{3v3n_m4tr1x_c4n_3ncrypt}

Description: Custom matrix-based cipher where elements are swapped.

Solution: The encryption swaps columns in a 4-column matrix:

• Columns 0 and 3 swap

• Columns 1 and 2 swap

To decrypt, we simply reverse the swapping:

import numpy as np

cipher = "114,97,112,83,118,51,123,107,109,95,110,51,49,114,116,52,52,99,95,120,110,51,95,110,112,121,114,99,32,32,125,116,"
ascii_values = [int(x) for x in cipher.split(',') if x]

rows = len(ascii_values) // 4
m = np.array(ascii_values).reshape(rows, 4)

# Reverse the swapping
for row in m:
    row[0], row[3] = row[3], row[0]
    row[1], row[2] = row[2], row[1]

flag = ""
for i in range(rows):
    for j in range(4):
        flag += chr(m[i, j])

print(flag)  # Spark{3v3n_m4tr1x_c4n_3ncrypt}

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