Online transactions – Major security concern.
Address of the secured website/online store always starts with http(s). So 
before you enter any transaction details on the trasanction page, check if the page is secured with the certificate verified. In the web browser: Internet Explorer or FireFox or Opera or Safari etc., you will see a lock icon (lockpad) in the Security Status bar. In IE the Security Status bar is located on the right side of the address bar.
The certificate that is used to encrypt the connection also contains information about the identity of the website owner or organization. To get the more information about the installed SSL certificate, you can click the lock to view the identity of the website.
If everything is okey you are in safe hands.
Happy shopping!