home.php

<?php

    $var = $_GET['id'];
    echo "Encrypted Text : ".$var."<br><br><br>";
    
    function encrypt_decrypt($action, $string) {
        $output = false;

        $encrypt_method = "AES-256-CBC";
        $secret_key = 'sadgjakgdkjafkj';
        $secret_iv = 'This is my secret iv';

        $key = hash('sha256', $secret_key);
        
        $iv = substr(hash('sha256', $secret_iv), 0, 16);

        if ( $action == 'encrypt' ) {
            $output = openssl_encrypt($string, $encrypt_method, $key, 0, $iv);
            $output = base64_encode($output);
        } else if( $action == 'decrypt' ) {
            $output = openssl_decrypt(base64_decode($string), $encrypt_method, $key, 0, $iv);
        }

        return $output;
    }
    
    $decrypted_txt = encrypt_decrypt('decrypt', $var);
    echo "Decrypted Text =" .$decrypted_txt. "\n";

    
?>