Adding a Custom SSL Certificate
Merchants who accept credit cards are required by the Payment Card Industry (PCI) to process transactions on a securely encrypted channel. An SSL certificate verifies that all transactions take place over the encrypted secure socket layer (SSL). The secure session is established when the customer begins the checkout process, or whenever other sensitive information is shared. During the secure transaction, a padlock icon appears in the address bar of your browser, and the URL prefix changes from http:// to https://.
A custom SSL certificate provides your customers with a seamless checkout experience from the security of your own “dot com” address. Otherwise, your customers are redirected to the shared secure channel on the Magento Go domain for the duration of their transactions.
Note: You must have a custom domain before you can purchase a security certificate for your store.