In computers based on a Debian operating system that uses Linux kernel, error messages similar to NO_PUBKEY may appear. This happens while using the Apt-Get command line tool, and this error is associated with the tool's update feature. This problem can be solved by simply keying in the appropriate commands.
gpg --keyserver pgpkeys.mit.edu --recv-key 010908312D230C5F
gpg -a --export 010908312D230C5F | sudo apt-key add -