https://crackinglandia.wordpress.com/2016/10/02/h4ck1t-ctf-2016-quals-crypt00perator-ethiopia-95-rev...

Original writeup (https://crackinglandia.wordpress.com/2016/10/02/h4ck1t-ctf-2016-quals-crypt00perator-ethiopia-95-revere-write-up/).