CircleConCTF 21'

CRT RSA

Challenge Points : 100 Points *Solved by :

Writeup

TL;DR - Hastard's Broadcast Attack

Script

from sage.all import *
from Crypto.Util.number import long_to_bytes
eval(open("crt_rsa").read())
c = [ct_1,ct_2,ct_3]
n = [n_1,n_2,n_3]

print(long_to_bytes(gmpy.root(CRT(c,n),3)[0]))

Flag

flag{infi_nite_jes_t}