Use office.js open an encrypted workbook

I need to have an office.js add-in create an Excel workbook from the bytes of a workbook that has been encrypted with a password that must remain unknown to the user.   

I can create a workbook using:

Excel.createWorkbook(base64)

 However, this prompts the user to enter the password.  I'd like to be able to specify the password in the code so the workbook gets created without prompting the user to enter it.