For 4 days now, users have been unable to update the repositories and install new software using the previously released Kali Linux key 827C8569F2518CC677FECA1AED65462EC8D5E4C5, receiving an error:
The problem is that the developers lost the previous key, and there is no certificate system for SSL connections. The bare key is transmitted, taking into account the trust that it was downloaded via HTTPS or other reliable sources. Therefore, there is no mechanism for revoking CRL/OSCP certificates, and the developers had to put a new signature on all repositories.
To resolve the error, users are prompted to install a new key using the command:
sudo wget https://archive.kali.org/archive-keyring.gpg -O /usr/share/keyrings/kali-archive-keyring.gpg 
After that, the repository must be verified with a new public key and the packages must be updated successfully. Those who have recently reinstalled the OS will not be affected by this change, since the new keys are already included in the distributions of all versions. Unfortunately, a similar case already affected Kali Linux repositories in 2018, when repositories had to be frozen and packages were unavailable.
For such cases, we recommend using backup package managers with their repositories, for example snap, npm, pip and others, which will ensure fault tolerance in such events.
