Kali Linux (Raspberry Pi 3b) update failed with the above problem

Invalid signature for Kali Linux repositories: "The following signatures were Invalid:expkeysig Ed444ff07d8d0bf6 Kali Li Nux Repository "

Today intends to update Kali, found that the above problems, Google was found to be due to the digital signature expired:

Note that if you do not update the Kali installation (TSK2) for a period of time, you will want to receive a GPG error (ED444FF07D8D0BF6) about the expiration of the repository key. Fortunately, this issue can be resolved quickly by running the following as root:

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

It will succeed in a few seconds and then run again.

apt-get update && apt-get upgrade && apt-get dist-upgrade

We'll be able to update.

Kali Linux (Raspberry Pi 3b) update failed with the above problem