Installing R from CRAN Ubuntu repository: No Public Key Error

I am on R version 2.13 and would like to update to a newer version in order to use some packages that depend on R>= 2.14.

I have the line to my sources.list file as found described here. I then navigate to the terminal and type:

sudo apt-get update

and get the following error when trying to update R on the CRAN mirror closest to me:

>Reading package lists... Done > W: GPG error: http://lib.stat.cmu.edu oneiric/ Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 51716619E084DAB9

Any idea how to debug this error?

The simplest solution that worked for me was from Emre Sahin in this thread:

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys E084DAB9 

Like @Ben Bolker commented (sorry I hijacked your commented, but the correct answer was not yet posted), in [the description][1] of the debian package repo there is a section secure apt which says:

> SECURE APT > > The Debian backports archives on CRAN are signed with the key of > "Johannes Ranke (CRAN Debian archive) <[email protected]>" with key > ID 381BA480. You can fetch this with > > gpg --keyserver subkeys.pgp.net --recv-key 381BA480 or > alternatively, using another key server, > > gpg --keyserver pgp.mit.edu --recv-key 381BA480 If this doesn't > work, it might be due to a firewall blocking port 11371. > Alternatively, you can search for 0x381BA480 at > http://keyserver.noreply.org/ or http://pgp.mit.edu/ and copy the key block into a plain text > file, named, for instance, jranke_cran.asc. > > If receiving the key with gpg did work, you need to export it to a > text file > > gpg -a --export 381BA480 > jranke_cran.asc In both cases you need > to make the key known to the apt system by running > > apt-key add jranke_cran.asc as root.

If you have not already done this, this will probably fix your issue. [1]: http://cran.r-project.org/bin/linux/debian/

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys KEYID

and replace KEYID with the number shown in the error message.

Thanks to Philipp Burckhardt, I got it fixed.

Try this:

gpg --keyserver pgpkeys.mit.edu --recv-key 51716619E084DAB9  
gpg -a --export 51716619E084DAB9 | sudo apt-key add -

Here is a step-by-step answer that might be easier to follow.

1. Fetch the key (the last 8 digits in the warning message):

    gpg --keyserver pgp.mit.edu --recv-key E084DAB9
   

The output should look like this:

    gpg: requesting key E084DAB9 from hkp server pgp.mit.edu
    gpg: key E084DAB9: public key "Michael Rutter <[email protected]>" imported
    gpg: Total number processed: 1
    gpg:               imported: 1  (RSA: 1)

2. Add the key (superuser access required):

    gpg -a --export E084DAB9 | sudo apt-key add -

4. Update the repositories:

    sudo apt-get update

There should be no warning about the missing key now.

I encountered the same issue and the only solution I found, perhaps due to a firewall, was to use the helpful Y PPA Manager. The two steps below outline has worked on Ubuntu 15.04.

1. First install the Y PPA Manager:

   sudo add-apt-repository ppa:webupd8team/y-ppa-manager sudo apt-get update sudo apt-get install y-ppa-manager

2. Then fetch missing keys by running the Y PPA Manager:

   y-ppa-manager

> Click "Advanced" >> Next, click "Try to import missing GPG keys"

Finally, update again to check if it works:

sudo apt-get update

Much like others posted above, this one-liner seems to work well on Debian 6:

sudo apt-key adv --keyserver hkp://pgp.mit.edu:80 --recv-keys 381BA480

Executing: gpg --ignore-time-conflict --no-options
--no-default-keyring --secret-keyring /etc/apt/secring.gpg --trustdb-name /etc/apt/trustdb.gpg --keyring /etc/apt/trusted.gpg --primary-keyring /etc/apt/trusted.gpg --keyserver hkp://pgp.mit.edu:80 --recv-keys 381BA480 
gpg: requesting key 381BA480 from hkp server pgp.mit.edu 
gpg: key 381BA480: public key "Johannes Ranke (CRAN Debian archive) <[email protected]>" imported 
gpg: no ultimately trusted keys found 
gpg: Total number processed: 1 
gpg:      imported: 1

This solved my problem

$ wget -q -O - https://archive.kali.org/archive-key.asc | apt-key add

It had to use a longer identifier for the key.

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys E298A3A825C0D65DFD57CBB651716619E084DAB9

The issue seems to be a duplicated key ID on the server. See the instructions from the CRAN and more background info on this post by Michael Rutter.

The easiest fix is to simply follow the instructions from https://cran.r-project.org/bin/linux/ubuntu/. Run this as sudo:

# update indices
apt update -qq
# install two helper packages we need
apt install --no-install-recommends software-properties-common dirmngr
# add the signing key (by Michael Rutter) for these repos
# To verify key, run gpg --show-keys /etc/apt/trusted.gpg.d/cran_ubuntu_key.asc 
# Fingerprint: 298A3A825C0D65DFD57CBB651716619E084DAB9
wget -qO- https://cloud.r-project.org/bin/linux/ubuntu/marutter_pubkey.asc | sudo tee -a /etc/apt/trusted.gpg.d/cran_ubuntu_key.asc
# add the R 4.0 repo from CRAN -- adjust 'focal' to 'groovy' or 'bionic' as needed
add-apt-repository "deb https://cloud.r-project.org/bin/linux/ubuntu $(lsb_release -cs)-cran40/"