The following signatures couldn't be verified because the public key is not available while updating sudo apt update

Question

I am trying to install some application on Ubuntu 20.04, for that I am trying to run command on terminal

$ sudo apt update

and I have got following error

Err:1 http://dl.google.com/linux/chrome/deb stable InRelease                                
  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 78BD65473CB3BD13

Exoteric

Answer 1

I am got the same issue while running the below command

$ sudo apt update

In your case, you can follow below option to resolved these issue.

1. sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 78BD65473CB3BD13

   Or

2. sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 78BD65473CB3BD13

In first option, we don't have to decide which port should be or you can go with second option. Either way, both will work.

Exoteric

Tip: this is not limited to ubuntu packages (myself had problems updating influxdb and grafana) – Gallivant

What is the uppercase string? – Elijah

The uppercase string is what you'll get in the error message. In the case of the OP, it was this string as they got the error The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 78BD65473CB3BD13. – Redan

Answer 2

Warning: apt-key is deprecated. Manage keyring files in trusted.gpg.d instead (see apt-key(8)).

To avoid the warning, add the package specific file with the key to the /etc/apt/trusted.gpg.d/ directory. The keys can be in several file formats like .asc, .gpg etc. To add new PUBKEY:

    wget -qO- URL/PUBKEY.asc | sudo tee /etc/apt/trusted.gpg.d/APPNAME.asc

If the key is in the binary ('armored') format, dearmor it first:

    curl -s URL/PUBKEY.gpg | sudo gpg --dearmor | sudo tee  /etc/apt/trusted.gpg.d/APPNAME.gpg --import

Reference: apt-key deprecated

Filide

This should have been a comment, not an answer. – Seraglio

Note that placing keys in /etc/apt/trusted.gpg.d/ isn't any better than using apt-key (security wise), see the accepted answer to the referenced question. – Lutenist

Answer 3

2024 update

Google has a new suggested way of installing/updating it's keys if it doesn't happen automatically on your system.

wget -q -O - https://dl.google.com/linux/linux_signing_key.pub | sudo tee /etc/apt/trusted.gpg.d/google.asc >/dev/null

If your system is ASCII-armored, use this command instead

wget -q -O - https://dl.google.com/linux/linux_signing_key.pub | sudo tee /etc/apt/trusted.gpg.d/google.asc >/dev/null

Then run sudo apt update again and the errors related to google package signatures should be gone.

Note: for APT and RPM based systems, you'll find more details following the source link.

Source: https://www.google.com/linuxrepositories/

Cohdwell