PHP - How To I Secure My Imploded Data?

<div id="image-upload">
<h2>Upload your image</h2>
<form action="upload.php" method="post" enctype="multipart/form-data"> 
Upload:<br><br> 
<input type="file" name="image"><br><br>
Image Title:<br><br> 
<input type="text" name="image_title"><br><br> 
<input type="submit" name="submit" value="Upload"> 
</form>
	
	
<?php
include("upload_file.php");

function GetImageExtension($imagetype)
{
if(empty($imagetype)) return false;
switch($imagetype)
{
case 'image/bmp': return '.bmp';
case 'image/jpeg': return '.jpg';
case 'image/png': return '.png';
default: return false;
}
}
		 
			 
if ($_FILES['image']['error'] !== UPLOAD_ERR_OK) {
die();
}

$extension = getimagesize($_FILES['image']['tmp_name']);
if ($extension === FALSE) {
die("<br><font color='#8B0000'>Unable to determine image typeof uploaded file</font>");
}

if (($extension[2] !== IMAGETYPE_GIF) && ($extension[2] !== IMAGETYPE_JPEG) && ($extension[2] !== IMAGETYPE_PNG)) {
die("<br><font color='#8B0000'>Only images are allowed!</font>");
}
			 
			 
			 			 
if (!empty($_FILES["image"]["name"])) {

$file_name=$_FILES["image"]["name"];
$temp_name=$_FILES["image"]["tmp_name"];
$imgtype=$_FILES["image"]["type"];
$ext= GetImageExtension($imgtype);
$imagename=$_FILES["image"]["name"];
$target_path = "../../images/upload/".$imagename;
$title = $_POST["image_title"];

		
if(move_uploaded_file($temp_name, $target_path)) {
$query_upload="INSERT into `images_tbl` (`images_path`,`submission_date`,`image_title`) VALUES 
('".$target_path."','".date("Y-m-d")."','".$title."')";

mysql_query($query_upload) or die("error in $query_upload == ----> ".mysql_error()); 
echo '<br>Image uploaded!';
}else{
echo '<br><font color="#8B0000">Only images are allowed!</font>';
} 
}
?>

Are there any PHP hashes that are extremely secure and that CANNOT be reverse-engineered?

Hi!

I wanna know what is the best way to secure my inputs?

Now I'm using something like this function:

public function z($var) {
        $result1 = htmlspecialchars($var);
        $result = mysqli_real_escape_string($this->conn, $result1);
        return $result;
    }

but I don't know how secure it is from all inputs... It couldn't be that with that my site is completely secure...

So I wanna know what else I should use...

I found something about PHP sanitize filters and similar... Same for mail, should I use that for e-mail, what should I use for e-mails as I think this 2 codes will brake character @ necessary for emails.

Any suggestion is welcome

Thanks

		if ( proceed ) {
			//console.log('All the conditions have been met.');
			var data = $('#registerForm input').serialize(); // Put form data into serialize format:

			/* Save Function by grabbing & sending data to register.php */
			$.post($('#registerForm').attr('action'), data , function(info) {
				console.log(info);
				//$('#result').text(info); // Display the result back when saved: 
			}); // End of Save:
			
		} else {
			console.log('There is a problem somewhere.');
		}

if (isset($_POST['username'])) {
	$userType = 'public';
	$username = $_POST['username'];
	$realname = $_POST['realname'];
	$email = $_POST['email'];
	$password = password_hash(trim($_POST['password']), PASSWORD_BCRYPT, array("cost" => 15));

	$query = 'INSERT INTO users (userType, username, realname, email, password, dateAdded) VALUES (:userType, :username, :realname, :email, :password, NOW())';
	$stmt = $pdo->prepare($query);

	try 
	{
		$result = $stmt->execute(array(':userType' => $userType, ':username' => $username, ':realname' => $realname, ':email' => $email, ':password' => $password));
		if ($result) {
			echo 'Data Successfully Inserted!'; 
		}
	} 
	catch(PDOException $error) 
	{
		if (substr($error->getCode(), 0, 2) == SQL_CONSTRAINT_VIOLATION) {
			$errorMsg = 'The username already exists.';
		} else {
					throw $error; // some other error happened; just pass it on.	
				}		
			}
			
		}