Sometimes, when you upgrade the system, an error may occur GPG, which means that the key of some of the repository has changed or something happened to him. In this short article I will show how to quickly solve et this problem.
So, once you run the command to update the indexes of the packages in the repository, we have known the command:
sudo apt update
W: GPG error: http://ppa.launchpad.net trusty Release: The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY D35164147CA69FC4
Fix this misunderstanding
Method –1
Look at the value NO_PUBKEY, in my example this value D35164147CA69FC4 and insert this value into the command to make it as I have:
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys D35164147CA69FC4
Open a terminal and run the following single command:
sudo apt-key adv --recv-keys --keyserver keyserver.ubuntu.com `sudo aptitude update 2>&1 | grep -o ‘[0-9A-Z]\{16\}$’ | xargs`
Method –3
Try to use a powerful utility for working with repository Y PPA Manager
Good Luck!!!
Signature by key E1A38B8F144675D060EA666F3EE67F3D0FF405B2 uses weak digest algorithm (SHA1)
It's not terrible, just some repositories still use SHA1. This is just a warning from your operating system. In previous versions these warnings no, it's new thing.
This post doesn’t explain what these commands mean. Doing them without any checking may “undermine the apt-secure infrastructure” according to the apt-key man page. Find another source of information if you have problems.