Hint bro variables should never be used for echo print unless defined but that still is risky. If i am wrong i'll bow down and look back through my libary of life and tell you i was wrong. 98.7% I am correct though. I know you take security serious i just was passing over some info i learnt when i 15years old security and an idea.
I used this when i was 13yrs old but only wanted it to host so i could give out free html / css scripts.
http://phorum.org learnt something unique about it once i found again on my birthday it is hackproof and bulletproof been round since 98 i believe the year after md5 was hacked.
If anyone truely cared about security would sha5() with double_check() not sha1, sha2, sha3, sha4 lol