You must set up GPG signing before continuing.
sudo apt install -y dpkg-sig To demonstrate signing, we need a file to sign.
sudo apt install curl curl -fSsl http://ftp.us.debian.org/debian/pool/main/h/hello/hello_2.10-2_amd64.deb -o hello_2.10-2_amd64.deb dpkg-sig --sign builder hello_2.10-2_amd64.deb dpkg-sig --verify hello_2.10-2_amd64.deb