Error during signature verification while updating docker.

[mbhat2025]

Problem description

To update docker, command used :- sudo apt-get update

Faced this error.

Err:1 https://download.docker.com/linux/ubuntu bionic InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 7EA0A9C3F273FCD8 Hit:2 http://in.archive.ubuntu.com/ubuntu bionic InRelease
Hit:3 http://us.archive.ubuntu.com/ubuntu bionic InRelease
Hit:4 http://in.archive.ubuntu.com/ubuntu bionic-security InRelease
Hit:5 http://in.archive.ubuntu.com/ubuntu bionic-updates InRelease Reading package lists... Done W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://download.docker.com/linux/ubuntu bionic InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 7EA0A9C3F273FCD8 W: Failed to fetch https://download.docker.com/linux/ubuntu/dists/bionic/InRelease The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 7EA0A9C3F273FCD8 W: Some index files failed to download. They have been ignored, or old ones used instead.

Should i give same comments in both
/etc/apt/sources.list.d/additional-repositories.list /etc/apt/sources.list.d/docker.list

How to rectify?

[mrichtsfeld]

For this running this command fixed the issue:

chmod a+r /usr/share/keyrings/docker-archive-keyring.gpg

[wonbug]

Fresh Debian 11.3 install with umask 077 as the default.

Tried the chmod trick but get the same error from apt. Simply can't install Docker on Linux.