Before you start entering your card details online, there are a few checks you can do to make sure the page is secure. First of all, make sure that the 'http' within the URL is changed to 'https'. Also look out for a padlock sign next to the URL or on the lower right of your web browser. It should be in a locked state as opposed to unlocked. Double clicking the padlock symbol will show you more detailed security information for the site.