huge commit

2026/cscg/crypto/punkhash/.python-version

@@ -0,0 +1 @@
+3.13

2026/cscg/crypto/punkhash/crack.sage

@@ -0,0 +1,69 @@
+from Crypto.Cipher import AES
+from Crypto.Util.Padding import unpad
+
+# Given data
+p = 161435094849208186723743776068899835990543
+factors = [
+    156186292768571019331898663060909752711843,
+    109417470692453243484139400223645310959791,
+    93089433143062722427906401287402408530212,
+    28547969321924826217366869381297180095037,
+    8782064060721059630464173504550123514711,
+    102955100934149078143279795799942076169546,
+    6414672390685577718586273505396597123970,
+    104333325295219441337759136041049892760564,
+    112152969625868065689337753377527032666195,
+    73628881014191725621637709513252461493920,
+    55767305113105638821720350052172401226595,
+    151443380055257227298905238183594975661210,
+    154754427703287717852463872100570391036124,
+    109309350493404368756996675514019660378226,
+    72830920510645561848991903607768750782945,
+    140601680236381413682085702731572037454013
+]
+h = 55699848449950859593116400319282899455819
+enc_flag = bytes.fromhex("62c4cc8d98f1cfbc92d0315fc939b464614c7c96cfc956b0c8a44eeda15e4856fcf87710f97b445b4c4986794666fa391eeaf70963ea8f522c5b3866b7e153b6")
+
+n = len(factors)
+W = 2**256  
+
+# --- THE FIX: Center the search space around 0 ---
+OFFSET = 128
+h_centered = (h - OFFSET * sum(factors)) % p
+
+# Build an 18x18 Matrix
+M = Matrix(ZZ, n + 2, n + 2)
+
+for i in range(n):
+    M[i, i] = 1
+    M[i, n + 1] = factors[i] * W
+
+M[n, n + 1] = p * W
+
+M[n + 1, n] = 1
+M[n + 1, n + 1] = -h_centered * W
+
+# Run LLL Algorithm
+L = M.LLL()
+
+found = False
+for row in L:
+    if row[n] in [1, -1]:
+        y_vals = list(row[:n])
+        
+        # If flipped by LLL, flip it back
+        if row[n] == -1:
+            y_vals = [-y for y in y_vals]
+            
+        preimage = [y + OFFSET for y in y_vals]
+            
+        if all(0 <= x < 256 for x in preimage):
+            key = bytes(preimage)
+            cipher = AES.new(key, AES.MODE_ECB)
+            flag = unpad(cipher.decrypt(enc_flag), 16).decode()
+            print(flag)
+            found = True
+            break
+
+if not found:
+    print(":/")

2026/cscg/crypto/punkhash/data.json

@@ -0,0 +1,23 @@
+{
+    "p": 161435094849208186723743776068899835990543,
+    "factors": [
+        156186292768571019331898663060909752711843,
+        109417470692453243484139400223645310959791,
+        93089433143062722427906401287402408530212,
+        28547969321924826217366869381297180095037,
+        8782064060721059630464173504550123514711,
+        102955100934149078143279795799942076169546,
+        6414672390685577718586273505396597123970,
+        104333325295219441337759136041049892760564,
+        112152969625868065689337753377527032666195,
+        73628881014191725621637709513252461493920,
+        55767305113105638821720350052172401226595,
+        151443380055257227298905238183594975661210,
+        154754427703287717852463872100570391036124,
+        109309350493404368756996675514019660378226,
+        72830920510645561848991903607768750782945,
+        140601680236381413682085702731572037454013
+    ],
+    "hash": 55699848449950859593116400319282899455819,
+    "enc_flag": "62c4cc8d98f1cfbc92d0315fc939b464614c7c96cfc956b0c8a44eeda15e4856fcf87710f97b445b4c4986794666fa391eeaf70963ea8f522c5b3866b7e153b6"
+}

2026/cscg/crypto/punkhash/generate.py

@@ -0,0 +1,34 @@
+#!/usr/bin/env python3
+
+import json
+import random
+
+from Crypto.Cipher import AES
+from Crypto.Util.number import getPrime
+from Crypto.Util.Padding import pad
+
+FLAG = "dach2026{xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx}"
+
+pbits = 137
+p = getPrime(pbits)
+key_bits = 16
+
+# Generate hash of the key
+factors = [random.SystemRandom().randint(0, p-1) for _ in range(key_bits)]
+preimage = [random.SystemRandom().randint(0, 0xff) for _ in range(key_bits)]
+hash = sum([factors[i] * preimage[i] % p for i in range(key_bits)]) % p
+
+# Encrypt flag
+key = bytes(preimage)
+cipher = AES.new(key, AES.MODE_ECB)
+enc = cipher.encrypt(pad(FLAG.encode(), 16)).hex()
+
+data = {
+    "p": p,
+    "factors": factors,
+    "hash": hash,
+    "enc_flag": enc
+}
+
+with open("data.json", "w") as f:
+    json.dump(data, f, indent=4)

2026/cscg/crypto/punkhash/pyproject.toml

@@ -0,0 +1,7 @@
+[project]
+name = "punkhash"
+version = "0.1.0"
+description = "Add your description here"
+readme = "README.md"
+requires-python = ">=3.13"
+dependencies = []

2026/cscg/crypto/punkhash/uv.lock

@@ -0,0 +1,8 @@
+version = 1
+revision = 3
+requires-python = ">=3.13"
+
+[[package]]
+name = "punkhash"
+version = "0.1.0"
+source = { virtual = "." }