RPi Debian NOPUBKEY Issue - Solution

Raspberry Pi 3 runs Raspian Jessie which is debian operating system that uses linux kernal, when you try to run following command,

sudo apt-get update

Error messages may come up like 'NO_PUBKEY'.

This happens while using the 'apt-get command line tool' and this error is associated with the tool's update feature.

The new feature in the Apt-Get package management tool guarantees the authenticity of the server before updating the Debian OS. That's why the error 'NO_PUBKEY' pops up. This problem can be solved by keying in the appropriate commands.

ISSUES ON - [APT-GET UPDATE]

W: GPG error: ftp://ftp.debian.org/ testing Release:       
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 010908312D230C5F      

W: There is no public key available for the following key IDs:      
010908312D230C5F

SOLUTION

This is a new feature of the apt-get system that guarantees the authenticity of servers for updating Debian.

Replace the key as displayed on the error.

sudo gpg --keyserver pgpkeys.mit.edu --recv-key 010908312D230C5F 
sudo gpg -a --export 010908312D230C5F | sudo apt-key add -

you can run the following command now to update the packages on rpi,

sudo apt-get update

Update should be successful.