https://piggybird.net/2016/11/hack-the-vote-2016-write-up-the-best-rsa-crypto-250/

or

https://github.com/duc-le/ctf-writeups/blob/master/2016_Hack_The_Vote/crypto/250_The_Best_RSA/writeu...

Original writeup (https://piggybird.net/2016/11/hack-the-vote-2016-write-up-the-best-rsa-crypto-250/).