If I encrypt a file with
gpg -c file.zip, and change the filename. Is there any way I can restore the filename as I used as a password. or the name encrypted to?
gpg -c file.zip does encode the input file name in the encrypted packet.
The gpg man page documents a few relevant options:
Use string as the name of file which is stored in messages.
This overrides the default, which is to use the actual filename of the file being encrypted.
Try to create a file with a name as embedded in the data. This can be a dangerous option as it allows to overwrite files.
This defaults to no.