125

When performing apt-get update, I get the following error:

root@ADS3-Debian6:/home/aluno# apt-get update
Atingido http://sft.if.usp.br squeeze Release.gpg
Ign http://sft.if.usp.br/debian/ squeeze/contrib Translation-en
Ign http://sft.if.usp.br/debian/ squeeze/contrib Translation-pt
Ign http://sft.if.usp.br/debian/ squeeze/contrib Translation-pt_BR

(...)

Obter:10 http://security.debian.org squeeze/updates/non-free i386 Packages [14 B]
Baixados 612 kB em 4s (125 kB/s)                    
Lendo listas de pacotes... Pronto
There is no public key available for the following key IDs: 8B48AD6246925553
  • 2
    ... and that string you elided is an important bit. It'd let us identify which keys you're missing (assuming installing the keyring packages—preferably from trusted media—that ruda suggested doesn't help) – derobert May 14 '13 at 17:43
  • 1
    You shouldn’t let your cat walk on the keyboard like that.     :-)     ⁠ – G-Man Oct 27 '17 at 4:19
163

The other answers will work, or not, depending on whether or not the key '8B48AD6246925553' is present in the packages they indicate.

If you need a key, you have to get that key, and where to find it, it's in a key server (very probably any key server will do):

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 8B48AD6246925553
  • This worked for me too and not other answers here.. – Sai Kiran Apr 28 '16 at 4:54
  • @starbeamrainbowlabs now it is! =) – That Brazilian Guy May 3 '16 at 17:26
  • @ThatBrazilianGuy :D – starbeamrainbowlabs May 4 '16 at 18:10
  • 4
    Is there any way to determine if the received key is leggit such that I can do such a dangerous operation like adding global apt-trust to some arbitrary key? Is there any way to check the credibility of the key after it was received? Which are the steps to perform to do the key verification? For example, the only thing you have is ftp-master.debian.org/keys/ziyi_key_2002.asc so how do you get to the most current key without breaking the trust chain? – Tino May 13 '16 at 9:22
  • 1
    @ThatBrazilianGuy: The fact that it’s your question doesn’t give you the right to vandalize an answer. – G-Man Jan 16 at 3:42
76

I recommend that you follow @mariotomo's answer rather than the steps below:


According to There is no public key available for the following key ID, this will fix it:

sudo aptitude install debian-keyring debian-archive-keyring

References

  • The last 8 hex digits are shared with this, so it's probably complaining about wheezy. Unfortunate of the OP to have elided that: pub 4096R/46925553 2012-04-27 [expires: 2020-04-25] uid Debian Archive Automatic Signing Key (7.0/wheezy) <ftpmaster@debian.org> – Martin Dorey Jun 2 '13 at 0:56
  • 5
    Is debian-keyring really needed? It worked out for me with just debian-archive-keyring. – x-yuri Oct 5 '15 at 15:24
  • Not surprisingly, different hex numbers may require different solutions. I put quotation marks around the number in my Google search, to force a verbatim search for that number, and I landed at this page, which fixed my problem: reddit.com/r/linux4noobs/comments/4grdo7/… (@mariotomo's answer may have worked too—I didn't try) – Michael Scheper Apr 30 '16 at 13:29
36

I recommend:

$ sudo apt-get install debian-archive-keyring
$ sudo apt-key update

This is better than other approaches because it does not install debian-keyring, which is big and 99% of the time unnecessary.

  • 1
    This was all I needed - worked great for me! – harperville Nov 20 '15 at 19:53
  • Work like a charm ! – Wilbeibi Jul 20 '17 at 23:37
  • 1
    This was the better solution for me as it fits in with a Docker container better. However note that (at least in Docker) you have to install only this package first, then do a second apt-get update, then install the packages you really want. – Malvineous Oct 6 '17 at 3:40
17

The error There is no public key available for the following key IDs indicates a serious security issue: an operating-system package cannot be checked for integrity with its public key, because its public key is missing.

If the message were:

There is no public key available for the following key IDs: 1397BC53640DB551

You can use this command to find out which repository uses the key:

for n in `ls /var/lib/apt/lists/*gpg`; do echo "$n" ; gpg --list-packets "$n" | grep 1397BC53640DB551; done

Which in this example is the Google's repository for Chrome:

/var/lib/apt/lists/dl.google.com_linux_chrome_deb_dists_stable_Release.gpg

If you trust Google, its government, etc., you should find out where the key is and add it with:

wget -q -O - https://dl.google.com/linux/linux_signing_key.pub | apt-key add -
  • Fixed for me :) Thank you! But just curious, what was wrong? What does the first command do, and what does the second one do? Should this solve all problems? My issue was also with Google Chrome. – Rohan May 2 '16 at 2:33
  • And does the first command change anything with gpg? It says it created some conf file gpg.conf, and I do not know if I want that. – Rohan May 2 '16 at 2:39
  • The first does search for the key in your list of packets to see the offending packet. The second one downloads the key and add it to your system. The first command is not useful in this case, but it's good as a general approach. – Marco Sulla May 10 '16 at 22:04
3

I faced the same problem in Linux Mint (Kernel Version 3.13.0-24) and I was able to solve it using the commands :

gpg --recv-keys <the-reported-key>

gpg --export <the-reported-key> | apt-key add -

Points to be noted:

1) The commands were executed in order 2) The commands were exectued as root user

Courtesy this answer.

1

As an alternative:

$ sudo apt-get install debian-keyring debian-archive-keyring
$ sudo apt-key update
  • 6
    Please don't advertise your blog in your answers. That's what your bio is for. – slm Dec 6 '14 at 2:58
1

My answer is a slight upgrade (IMHO, YMMV) on @mariotomo (who I upvoted) in the following bash scriptlet

  • also uses gpg
  • parameterizes more
  • (also uses a different keyserver, though in this case I suspect it makes little difference)

You can also comment-out the eval line for a "dry-run": the scriptlet will then only show you what it intends to do, without actually doing it. Just be sure to change the value of NO_PUBKEY every time you use this (you can also change KEYSERVER as desired):

NO_PUBKEY='1397BC53640DB551' # CHANGE TO THE VALUE CITED IN YOUR ERROR MESSAGE!
KEYSERVER='keys.gnupg.net'

NO_PUBKEY_LEN="${#NO_PUBKEY}"
echo "NO_PUBKEY_LEN='${NO_PUBKEY_LEN}'"     # for sanity or debugging
# note following works because bash arrays have 0-based indices
NO_PUBKEY_2ND_HALF_START=$(( NO_PUBKEY_LEN/2 ))
echo "NO_PUBKEY_2ND_HALF_START='${NO_PUBKEY_2ND_HALF_START}'" # ditto
NO_PUBKEY_2ND_HALF="${NO_PUBKEY:${NO_PUBKEY_2ND_HALF_START}}"
echo "NO_PUBKEY_2ND_HALF='${NO_PUBKEY_2ND_HALF}'"             # ditto

for CMD in \
  'date' \
  "gpg --keyserver ${KEYSERVER} --recv-keys ${NO_PUBKEY_2ND_HALF}" \
  'date' \
  "gpg -a --export ${NO_PUBKEY_2ND_HALF} | sudo apt-key add -" \
; do
  echo -e "${CMD}"
  eval "${CMD}"
done
0

Run killall -q gpg-agent if the other solutions do not work. It may work.

I was getting a similar error for a PPA repository on Ubuntu 18.04 and after trying various solutions on the internet for the last month, I just stumbled on the gpg-agent and killed it. Then the PPA repositries started to update on doing sudo apt-get update. I know it may compromise security, but sometimes you need a package from a PPA, and GPG just doesn't let you. Later, you start the gpg-agent again, and things go back to normal.

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-1

This worked for me:

Quick remedy:

sudo rm -f /etc/apt/trusted.gpg

(Source)

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