#CakeCTF2023 import random import signal import os HANDNAMES = { 1: "Rock", 2: "Scissors", 3: "Paper" } def commit(M, m): while True: r = random.randint(2, 2**256) if r % 3 + 1 == m: break return M**r, r signal.alarm(1000) flag = os.enviro…

#UnionCTF 一般線形群上の離散対数問題 そしてこれは行列が対角化#### できないときには解ける import os from hashlib import sha1 from random import randint from Crypto.Cipher import AES from Crypto.Util.Padding import pad, unpad FLAG = b"union{…

#s4ctf_2021 #!/usr/bin/env sage from flag import flag def make_matrix(n): Zn = IntegerModRing(n) G = GL(2, Zn) while True: a, b, c, d = [randint(0, n - 1) for _ in range(4)] P = G([[a, b], [c, d]]) if P in G: return P def bpow(P, n): if n …

あなたがここを訪れたとき本当に見たかったのは多分一般線形群か対称群では？

#ASIS_CTF_Finals_2022 #!/usr/bin/env sage from Crypto.Util.number import * from flag import flag def genkey(nbit, k): p = getPrime(nbit) q = getPrime(nbit >> 2) n = p * q N = (p**k - 1) * (q**k - 1) while True: e = getRandomRange(1, n) if …

#kurenaif #seccon2021 from Crypto.Util.number import * from flag import flag p = getStrongPrime(512) q = getStrongPrime(512) n = p*q mid = len(flag) // 2 e = 65537 m1 = int.from_bytes(flag[:mid], byteorder='big') m2 = int.from_bytes(flag[m…