"Everything... is unreal?"

"What is reality? And how do you define it? The entire range of sensations: visual, tactile, olfactory—these are signals from receptors, electrical impulses received by the brain."

"So, it's all NULL?"

"No, it's all 0. Don't confuse it and don't forget the difference, otherwise, during the transformation, you'll end up in the wrong place."

s0 = [180, 78, 186, 89, 192, 69, 185]
s1 = [360, 256, 151, 266, 171, 286, 175]
s2 = [520, 425, 326, 215, 104, 212, 337]
for arr in (s0, s1, s2):
    for j in range(len(arr) - 1):
        print(chr(abs(arr[j+1] - arr[j])), end = '')

# admin_task1/flask-app/app.py
@app.route("/profile")
def profile():
    if "user" not in session:
        return redirect(url_for("login"))
    
    if session["user"] == ADMIN_USER:
        return render_template("profile.html", 
                             username=session["user"],
                             flag="flag{adm1n_artifact_rec0very_2025}")
    
    return render_template("profile.html", 
                         username=session["user"],
                         flag="Обычный пользователь - флага нет")

In the world of cyberpunk, where technology and information rule, the story of the search for a great train that could change the course of history has become the stuff of legend.

This train, hidden in the depths of the digital world, was the key to solving many mysteries and riddles. Many adventurers tried to find it, but all their attempts ended in failure. All they had was the mysterious string "ucfwsz," which they found in the most unexpected places.

No one knew what it meant, but everyone believed it was part of a cipher leading to the train. One day, a young hacker named Alex decided to take on this task. He spent countless hours exploring cyberspace, breaking into secure servers, and deciphering complex codes.

And finally, he found it—the great train.

Alex realized that the string "ucfwsz" was the key to finding the train, but it was only part of the coordinates. The key was a string that allowed him to locate a sector on the map. But before he could use this knowledge, he faced his final challenge.

The train's defense system was intelligent and ruthless. It knew Alex was approaching, and it tried to stop him.

But Alex was ready. He used all his skills and knowledge to bypass the defenses and reach the heart of the system.

In the end, Alex disappeared. His story became the beginning of a journey for all enthusiasts interested in both Alex's story and the search for the mysterious train.

import numpy as np
from pathlib import Path
import csv, re

HEX_RE = re.compile(r"0x[0-9A-Fa-f]+")

def load_mosi(path):
    vals = []
    with path.open() as f:
        r = csv.DictReader(f)
        for row in r:
            m = row["MOSI"].strip()
            m = HEX_RE.search(m).group(0)
            vals.append(int(m, 16))
    return vals

A = load_mosi(Path("spi_A.csv"))
B = load_mosi(Path("spi_B.csv"))

framesA = [A[i:i+4] for i in range(0, len(A), 4)]
B_trim = B[:-1]
framesB = [B_trim[i:i+7] for i in range(0, len(B_trim), 7)]
framesB = [f for f in framesB if len(f) == 7]

H = 8
W = 4 * len(framesA)

bufA = np.zeros((H, W), dtype=np.uint8)
bufB = np.zeros((H, W), dtype=np.uint8)

for i, frame in enumerate(framesA):
    for col, byte in enumerate(frame):
        x = i*4 + col
        for y in range(8):
            bit = (byte >> y) & 1
            bufA[H-1-y, x] = bit


bufX = bufA ^ bufB
H, W = bufX.shape
buf = 1 - bufX

with open("xor.ppm", "w") as f:
    f.write(f"P3\n{W} {H}\n255\n")
    for y in range(H):
        for x in range(W):
            v = 0 if buf[y, x] else 255  # 0 = black, 255 = white
            f.write(f"{v} {v} {v} ")
        f.write("\n")

from PIL import Image
import numpy as np

with open("xor.ppm", "r") as f:
    magic = f.readline().strip()
    w, h = map(int, f.readline().split())
    maxval = int(f.readline())
    nums = []
    for line in f:
        if not line.strip():
            continue
        nums.extend(map(int, line.split()))

nums = np.array(nums, dtype=np.int16)
pixels = nums.reshape(h, w, 3)[:, :, 0]
img = (pixels < 128).astype(np.uint8)
rot90 = np.rot90(img, k=1)
    
im = Image.fromarray((1 - rot90) * 255)  # nền trắng, chữ đen
im.resize((rot90.shape[1]*4, rot90.shape[0]*4), Image.NEAREST).save("xor_rot.png")

from PIL import Image
import numpy as np

img = Image.open("xor_rot.png")
w, h = img.size
scale = w // 8
new_w = 8
new_h = h // scale
img_small = img.resize((new_w, new_h), Image.NEAREST)
arr = np.array(img_small.convert("L")).T
bin_arr = (arr < 128).astype(int)
H, W = bin_arr.shape


values = []
for x in range(W):
    col = bin_arr[:, x]
    if not col.any():
        continue
    bits = ''.join('1' if b else '0' for b in col)
    values.append(int(bits, 2))


seg_to_hex = {
    0x3F: '0', 0x06: '1', 0x5B: '2', 0x4F: '3',
    0x66: '4', 0x6D: '5', 0x7D: '6', 0x07: '7',
    0x7F: '8', 0x6F: '9', 0x77: 'a', 0x7C: 'b',
    0x39: 'c', 0x5E: 'd', 0x79: 'e', 0x71: 'f',
}

hex_str = ''.join(seg_to_hex.get(v, 'c') for v in values)
cipher = bytes.fromhex(hex_str)
def swap(b): 
    return ((b & 0x0F) << 4) | (b >> 4)

pt  = bytes(swap(b) for b in cipher)
# b'}emmorf_tnaw_uoy_od_tahw_galfekaf_galfekaF{FTCM'

msg = pt[::-1].decode()
print(msg)
# MCTF{Fakeflag_fakeflag_what_do_you_want_fromme}

import pandas as pd, numpy as np

df = pd.read_csv("i2c.csv")
df["data_int"] = df["Data"].str.replace("0x","",regex=False).apply(lambda x: int(x,16))

pairs = []
for i in range(0, len(df), 2):
    if i+1 >= len(df): break
    reg = df.iloc[i]["data_int"]
    val = df.iloc[i+1]["data_int"]
    t   = df.iloc[i]["Time [s]"]
    pairs.append((t, reg, val))

frames = []
cur, prev_t = [], None
for t, r, v in pairs:
    if prev_t is not None and t - prev_t > 0.05:
        if cur: frames.append(cur)
        cur = []
    cur.append((r, v))
    prev_t = t
if cur: frames.append(cur)

patterns = []
for fr in frames:
    vals = {}
    for r, v in fr:
        vals[r] = v
    patterns.append([vals.get(i, 0) for i in range(1, 9)])

H = 8
W = len(patterns) * 8
img = np.zeros((H, W), dtype=np.uint8)

for i, pat in enumerate(patterns):
    for col, val in enumerate(pat):
        for row in range(H):
            bit = (val >> row) & 1
            img[row, i*8 + col] = bit

with open("i2c_flag.ppm", "w") as f:
    f.write(f"P3\n{W} {H}\n255\n")
    for r in range(H-1, -1, -1):
        for c in range(W):
            v = 0 if img[r, c] else 255
            f.write(f"{v} {v} {v} ")
        f.write("\n")

from PIL import Image
import numpy as np

# ---- đọc PPM (P3 ASCII) thành ma trận 0/1 ----
with open("i2c_flag.ppm", "r") as f:
    magic = f.readline().strip()
    w, h = map(int, f.readline().split())
    maxval = int(f.readline())

    nums = []
    for line in f:
        if not line.strip():
            continue
        nums.extend(map(int, line.split()))

nums = np.array(nums, dtype=np.int16)
pixels = nums.reshape(h, w, 3)[:, :, 0]
img = (pixels < 128).astype(np.uint8)

im = Image.fromarray((1 - img) * 255)  # nền trắng, chữ đen
im.resize((img.shape[1]*4, img.shape[0]*4), Image.NEAREST).save("i2c_flag_rot.png")

from Crypto.Util.number import long_to_bytes, bytes_to_long
s1 = bytes_to_long(b"MCTF{Fakeflag_fakeflag_what_do_you_want_fromme}")
s2 = int("4D0E17123D3D320554000A3E3337553E380C0102550B004306052B0B165B3C12302137443E2C452B15061D5E590800", 16)
res = s1 ^ s2
print(long_to_bytes(res))