Wanted to share this for some time as others might face the same issue in Taiwan:
The government, banks and many companies in Taiwan love encrypted PDFs for some reason.
Mostly, one’s ARC-number / ID-number will be used as a password - however, there are exceptions: Sometimes, it’s the passport number - sometimes it’s a combination of an account number / birthday and other data.
For me, this caused lots of headaches as I wanted to archive those PDFs without remembering the specific password for each file (and over the years, many of those numbers will change…).
What finally worked for me was a simple open-source tool to remove the password protection without modifying the actual document (another way seems to be to print the PDF to another PDF - but this caused the size to increase in many cases for me):
(If you’re on Windows, go to releases and download the one ending in -msvc32.zip. Then, unzip to a location on your computer).
Then, you simply call the program
qpdf.exe --decrypt --password=%password% "%inputFile%" "%outputFile%"
And voilá - the password is gone!
With the help of ChatGPT, I created a small shell script which allows me to drag&drop the file I want to encrypt into it, enter the password - and the rest will be handled automatically (Assuming you unzipped the program to C:\Program Files (x86)\qpdf-11.9.1-msvc32) - save as unprotect_pdf.bat on your computer and then simply double-click:
@echo off
setlocal enabledelayedexpansion
:Start
:: Ask for the input file path
echo Please enter the full path to the PDF file (including the extension):
set /p inputFile=
:: Remove enclosing quotes if provided
set inputFile=%inputFile:"=%
:: Check if the file exists
if not exist "%inputFile%" (
echo File does not exist. Please try again.
echo.
goto Start
)
:: Extract the directory and filename without extension
for %%F in ("%inputFile%") do (
set inputDir=%%~dpF
set inputFileName=%%~nF
)
:: Ask for the password
echo Please enter the password for the PDF file:
set /p password=
:: Set the output file path
set outputFile=%inputDir%!inputFileName!_unprotected.pdf
:: Run the qpdf command
"C:\Program Files (x86)\qpdf-11.9.1-msvc32\bin\qpdf.exe" --decrypt --password=%password% "%inputFile%" "%outputFile%"
:: Check the result
if %errorlevel% equ 0 (
echo PDF password removed successfully.
echo The unprotected file is saved at: "%outputFile%"
) else (
echo Failed to remove the password. Please check the input file and password.
)
:: Loop back to the start
echo.
goto Start
Hope this helps someone!