The post was added to the "Barcode" forum so I am assuming the question in in regards to encryption of the data inside the barcode itself.
The data that is pushed into the barcode is in clear-text and is not encrypted. There is no encryption feature. Due to the fact that the data itself is typically seen on the form that has been printed, it may not be a requirement. If someone has the paper-form, they have the data.
If you would like to protect some of the data then I would suggest submitting the data that needs protecting via https prior to printing and then simply including a unique identifier in the barcode. Once the form is received, the paper is scanned not for the data, but for the unique identifier confirming the reception of the signed document (for example).