I was searching for RSA in php. Encrypt/decrypt text with RSA in php and in this site I found what I where searching for: Encrypt and Decrypt text with RSA in PHP
But the first and second answer is different! The first answer is a library (external file) but the second answer is a build-in command, openssl_public_encrypt(); .
So what the different about the library (external file) and the openssl_public_encrypt(); . Because the library (external file) can encrypt with RSA and only RSA, but the second one is openssl! I don't understand what got openssl with RSA doing!