You could write custom code that removed the sensitive data from the Formidable Fields when the form is submitted, and then save it to a Cookie. Further code would be required to read the data from the Cookie and populate the fields when editing the entry. If mandatory fields are used then placeholder values could be inserted. Have you considered encrypting the data in the fields rather than saving them to a Cookie. Cookies are meant to be opened and read and are highly insecure. Passwords and other sensitive information should not be stored in a Cookie. The contents could be read by malware, virus or hacker.