#bsidesahmedabadctf_2021 from Crypto.Util.number import getPrime from hashlib import sha256 import random def gen_parameters(): p = getPrime(512) q = getPrime(512) N = p * q a = -3 while True: b = random.randint(0, N) if (4*a**3 + 27*b**2)…

#bsidesahmedabadctf_2021 import os import hashlib from Crypto.Util.number import getPrime, getRandomNBitInteger from itertools import product def floor_sum(n: int, m: int, a: int) -> int: """Fast calculation for sum([a * i // m for i in ra…

#bsidesahmedabadctf_2021 import os from Crypto.Util.number import getPrime, getRandomNBitInteger flag = os.getenv("FLAG", "XXXX{sample_flag}").encode() m = int.from_bytes(flag, 'big') p = getPrime(512) y = pow(1 + p, m, p**3) assert m < p …

#bsidesahmedabadctf_2021 import os from Crypto.Util.number import getPrime, getRandomRange with open("flag.txt", "rb") as f: m = f.read().strip() m += os.urandom(111 - len(m)) m = int.from_bytes(m, "big") xs = [] for i in range(11): p = ge…