sudo apt-get update I often see this error:
W: GPG error: http://archive.hivemind.me all Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 3C962022012520A0
There are numerous reports and responses on AskUbuntu. They all require either (1) Lots of manual spelunking and multiple shell commands, or (2) Download of an external script, or (3) installation of a very-heavy GUI tool that is serious over-compensating for the problem.
Can someone who is not
#!/bin/bash challenged provide a simple one-liner to resolve the problem?