Using portable drive with GPG
I have a public/private key pair. I have the private key on a hardware AES encrypted USB drive. I can download the encrypted files on any computer, and need to be able to open them using the private key on my USB drive (private_key.asc). How can I do this, without importing the key into gpg (i.e. so it can't be used after I remove my USB key)?
Is there some kind of gpg switch where you select the private key file? Like
gpg --privatekey usb/private_key.asc --output file1.txt --decrypt file1.gpg