[This line of code has two cryptographic vulnerabilities](https://github.com/RNCryptor/RNCryptor-php/blob/f7ab514209fe476c4aa83a1df1fe9bb655e9e9b0/lib/RNCryptor/Decryptor.php#L99). 1. [The PHP "magic hash" evaluation flaw](http://blog.astrumfutura.com/2015/05/phps-magic-hash-vulnerability-or-beware-of-type-juggling) 2. [String comparison is vulnerable to timing attacks](http://blog.ircmaxell.com/2014/11/its-all-about-time.html) I'd suggest replacing it with `hash_equals()`. A [MIT licensed polyfill for `hash_equals()`](https://github.com/sarciszewski/php-future) already exists.