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When updating I got the following message:

W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used.
GPG error: http://dl.google.com/linux/chrome/deb stable Release:
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 6494C6D6997C215E
W: Failed to fetch http://dl.google.com/linux/chrome/deb/dists/stable/Release.gpg
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 6494C6D6997C215E
W: Some index files failed to download. They have been ignored, or old ones used instead.
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Calculating upgrade... Done

I'm on Ubuntu 16.04 and currently using Chrome 60.0.3112.90. Any suggestions? I'm also trying to install libimobiledevice but apparently the system is not reading the repository where I just added the PPA as I can't install it. Thanks in advance for any help.

marked as duplicate by Eric Carvalho, Tim, karel, David Foerster, heemayl Aug 5 '17 at 16:34

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

Apparently Google changed key for Chrome Linux repo. You can fix it by importing new repo key from Google:

wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | sudo apt-key add -

Now you should be able to update the system without any errors.

This works for APT-based distros: Debian, Ubuntu and derivatives (Linux Mint, Kubuntu, Xubuntu, Lubuntu, etc.)

For more info and a fix for RPM-based systems (Fedora, CentOS, openSUSE, etc.) see official Google Linux repositories page.

  • 5
    Is there a solution for maintainer to automate this process? I wonder how many users will solve this problem as Linux isn't only for geeks today? Maybe Google could make update more smooth. – PocketSam Aug 5 '17 at 3:37
  • @PocketSam There is a way for them to automate this process. Through an update. If they've stopped using their old key and you've missed the transition period where they used the old key but added the new key to the list, you've got a problem. – wizzwizz4 Aug 5 '17 at 9:20
  • 11
    There was no transition period: I run apt daily and this still happened. – Tobu Aug 5 '17 at 10:27
  • @Tobu Same for me. No transition - just fail. – Seann Aug 5 '17 at 13:59
  • 1
    Without google + stack-exchange (askubuntu, stack-overflow, etc.), this would be impossible even for experienced ("geeks"?) linux users. It's one of those very equalizing (humbling) issues that only appears to be easily resolved by experienced users. Sometimes ya just gotta google it -- as would be the case with any number of issues on any OS. – michael Aug 6 '17 at 9:58

try this:

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 6494C6D6997C215E

and

sudo apt-get update

This should fix it for you

wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | sudo apt-key add -

See: Google Chrome PPA upgrade invalid signature

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