Is there any way to encrypt specific parts of the form and not the whole document?

Looking to develop a sheet where the encryption only changes certain aspects (such as payment information) and leave the information fields exportable to excel.

Unfortunately, it is not possible to encrypt part of the form. Since the encryption is applied to the complete form, all the fields on the form will be encrypted. Please see the guide below that can help you with using form encryption.

https://www.jotform.com/help/344-Encrypted-Forms-and-How-to-Use-Them

Hope this information helps!