#cakectf2021 from Crypto.Util.number import getPrime, isPrime from hashlib import sha512 import random def getSafePrime(bits): while True: p = getPrime(bits - 1) q = 2*p + 1 if isPrime(q): return q def make_inivitation(): with open("flag.t…

#3kCTF-2021 from Crypto.Util.number import getPrime, long_to_bytes import hashlib, os, signal def xgcd(a, b): if a == 0: return (b, 0, 1) else: g, y, x = xgcd(b % a, a) return (g, x - (b // a) * y, y) def getprime(): while True: p = getPri…

#acsc2021 import random from Crypto.Util.number import * from Crypto.Util.Padding import pad from flag import flag p = getStrongPrime(512) q = getStrongPrime(512) n = p * q B = getStrongPrime(512) m = flag[0:len(flag)//2] print("flag1_len …

https://ctftime.org/task/7777 #pragyanctf #RabinCryptosystem #フェルマー法 Rabin has received a text from someone special, but it's all in ciphertext and he is unable to make head or tail of it. He requested her for a little hint, and she …

問題のソースコードは提供されていない 接続する度に N = pq を生成する がもらえる 好きな回数だけ RabinCryptosystem の復号ができる コードの一部だけもらえる import gmpy # Rabin Crypt def gen_modulus(nbit): while True: p, q = getPrime(nbit), get…

#SECCON_CTF_2022_Quals #kurenaif from Crypto.Util.number import * from Crypto.Random import * from flag import flag p = getPrime(512) q = getPrime(512) r = getPrime(512) n = p * q * r e = 2 * 65537 assert n.bit_length() // 8 - len(flag) > …