So, I just finished a Maven plugin that verifies each artifact in the build has been signed by a pinned pgp key. This would make it now difficult for an attacker to hijack another artifact's namespace.
https://exabrial.github.io/pgp-signature-check-plugin/
I tried to make the code AS straightforward as possible, using dependency injection to make testing easy. My Hope Is you start using this in your open source projects and at your job