Proving Your Identity To A Secure Website, With A Cellphone - Inexpensive Two Factor Authentication By: Virginia Konrad | - As a business owner with online websites, ecommerce applications or other services that require secure login by your customers, you understand how important it is to protect customer information. Information including credit card numbers, personal addresses, and other "personally identifiable information" (PII). Not only is it important to protect this information, but it's also important that access to sensitive areas of your website is protected against users you don't trust.