在页面之间移动表单数据的安全方法

I'm creating a form but I need to move data from form fields back and forth between pages. I don't need to save the data after the page is submitted yet.

I know that I can use sessions (server side)and sql but I don't know which one is more secure or easier to implement and when I use sessions I can get the data to move forward on the pages but when I hit the back button it disappeared.

is one better than the other? Is there a way to use sessions to move data back and forth between form fields?
page 1

<?php
//startssession
session_start();
//datatostore
$_SESSION['post-data'] = $_POST;
$test1 = $_POST["test1"] ;
$test2 = $_POST["test2"] ;
$test3 = $_POST["test3"] ;
$email = $_POST["email"] ;
?>

page 2

<?php
// starts the session.
session_start();
// data to pull and display in test text box.
$test1 = $_POST["test1"] ;
$test2 = $_POST["test2"] ;
$test3 = $_POST["test3"] ;
$email = $_POST["email"] ;
?>

Use sessions

when you hit the back button, that page probably does not have

session_start();

If you do not have that then you will not be able to access the session data.

This is fairly secure for what you are doing but I would also insure you have SSL on your site when you go to production for another layer of security.