Hi @lucian.cristian,
I use KNIME for a similar use case. I encrypt files with GnuPG from within KNIME via the Bash node (Community Extension NGS). In the Bash command you need
gpg.exe --output "C:\yourfile.xlsx" -d "C:\yourfile.xlsx.gpg",
whereas the execution directory points to the bin folder of your GnuPG installation.
If you are new to pgp-encryption, please make sure to read https://en.wikipedia.org/wiki/Pretty_Good_Privacy, because it doesn’t work like encrypting a zip-file with a password.
Kind regards
agaunt