Encrypted pdf

Can you load an encrypted pdf into Adobe Sign?  We have customers asking for Word documents so they can load the Word version instead of the encrypted pdf that we have given them.  We save the encrypted pdf to allow for signatures.  We use Professional Acrobat Abobe XI.   Is there a trick to customers being able to load and sign these encrypted pdfs?  It is against our policy to distribute the Word version and more customers are asking for the Word versions.