I want to do apt-get update on my debian machine. However, I am getting this.

Get:4 http://deb.torproject.org squeeze Release [2,951 B]
Err http://deb.torproject.org squeeze Release (other repositories that are OK) W: A error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://deb.torproject.org squeeze Release: The following signatures were invalid: KEYEXPIRED 1346668560 KEYEXPIRED 1346668560 KEYEXPIRED 1346668560 KEYEXPIRED 1346668560

W: Failed to fetch http://deb.torproject.org/torproject.org/dists/squeeze/Release

W: Some index files failed to download, they have been ignored, or old ones used instead.

What should I do? I don't want to remove the torproject repository, I still use tor time from time...

  • 1
    I was able to install that key successfully by first switching from user privileges to root privileges with sudo -s, then the key installs. then remember to exit back to user mode.
    – noobninja
    Commented Jan 29, 2020 at 8:31

3 Answers 3


Note: apt-key is deprecated

You could try updating the repository key. When I try to use the tor repository by adding this line to my sources.lst:

deb http://deb.torproject.org/torproject.org squeeze main

I get the following error:

W: GPG error: http://deb.torproject.org squeeze InRelease: The following 
signatures couldn't be verified because the public key is not available: 
NO_PUBKEY 74A941BA219EC810

So, the missing key is 74A941BA219EC810. To add (or update in your case) the key run:

sudo apt-key adv --recv-keys --keyserver keys.gnupg.net  74A941BA219EC810

You should now be able to run `apt-get update with no errors.

  • 5
    This worked for me: sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-key 74A941BA219EC810 Commented Oct 9, 2020 at 20:06
  • This worked for me: https://deb.torproject.org/torproject.org/A3C4F0F979CAA22CDBA8F512EE8CBC9E886DDD89.asc | gpg --dearmor | tee /usr/share/keyrings/tor-archive-keyring.gpg >/dev/null Commented 14 hours ago

Note: apt-key is deprecated

To find any expired repository keys and their IDs, use apt-key as follows:

apt-key list --keyid-format short | fgrep expired

You will get a result similar to the following:

pub   4096R/BE1DB1F1 2011-03-29 [expired: 2014-03-28]

The key ID is the bit after the / i.e. BE1DB1F1 in this case.

To update the key, as terdon points out, run

sudo apt-key adv --recv-keys --keyserver keys.gnupg.net BE1DB1F1
  • How to do this if the output now is pub rsa2048 2009-09-04 [SC] [expires: 2022-08-05] A3C4 F0F9 79CA A22C DBA8 F512 EE8C BC9E 886D DD89?
    – bomben
    Commented Dec 30, 2020 at 8:23
  • Use --keyid-format short. Have updated the answer.
    – kynan
    Commented Jan 1, 2021 at 16:15

You don't have to remove the repository but only disable it. This won't remove tor, just stop it from being updated.

In any case there's a problem with the repository's signature. You might try to remove the repository and add it again. It might solve the problem.

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