In Content Administration:
Click the Custom Fields entry in the content browser.
Click the Create a new entry icon in the toolbar.
Enter the required information. See the Custom Fields window.
Select whether to apply to Messages, Customers or Users.
Click the Save the changes made to this entry icon in the toolbar.
When the Response has encryption turned on, there is a check box in the Custom Fields page to enable encryption. This check box appears only if encryption is on.
Once you decide not to use encryption, it is recommended you do not turn it off. Instead, create a new field and map it to the appropriate form field.
You can learn more about encryption and PCI compliance by reading the About PCI Compliance topic.