Abstract: A technique for making post-signing modifications to a digitally-signed software application without invalidating the signature can be used to enhance a user experience when downloading the software application. An extension module extends the length of a signature section at the end of an executable file for the digitally-signed software application to form a storage section. A header adjustment module adjusts the header to indicate size of the storage section appended at the end of the executable file. A data insertion module inserts post-signing data into the storage section, and the validity of the digital signature is maintained without requiring the file to be re-signed after insertion of the post-signing data. Thus, a software vendor can add into the software user-specific data after the file has been signed, while still maintaining the signature's validity, so the software can be downloaded with minimal interruption to the user.