#MidnightSunCTF_2022_Quals #!/usr/bin/python3 from sys import stdin, stdout, exit from flag import FLAG from secrets import randbelow from gmpy import next_prime p = int(next_prime(randbelow(2**512))) q = int(next_prime(randbelow(2**512)))…

#CrewCTF_2022 ncすると一方的にメッセージが送られてくる how to factorize N given dするだけお def factorize(N, e, d): from math import gcd import gmpy2 k = d*e - 1 t = k while t % 2 == 0: t //= 2 g = 3 while True: x = pow(g, t, N) if x > 1: …

#tsg_live_ctf_10 #!/usr/bin/python3 from Crypto.Util.number import getPrime from flag import flag from sympy import nextprime dummy = b"GSTDIVE{this is a dummy}" dm = int.from_bytes(dummy,'little') assert(len(flag)==61) import secrets flag…

公開鍵暗号方式の一つ。典型的には以下のようなコードが登場する from Crypto.Util.number import getPrime, isPrime, inverse import os def keygen(): p = getPrime(512) q = getPrime(512) n = p*q e = 65537 d = inverse(e, (p-1)*(q-1)) return (n, e),…

#cyber_apocalypse_ctf_2021 from Crypto.Util.number import getPrime, inverse import random def main(): print("They want my private key, but it has sentimental value to me. Please help me and send them something different.") p = getPrime(512…