Pádraic Brady has a new post sharing some of his ideas around PHP package signing and a few possible ways to approach (and possibly solve) the problem.

We figured out how to write good code. We figured out how to write good code in a reusable way...for the most part. We figured out how to distribute and mix all that good reusable code in a sensible fashion. Can we now figure out how to do it all securely? [...] The problem with package signing from my perspective is tied up in a phrase most of you would know: The needs of the many outweigh the needs of the few. Thank you, Spock.

He compares two different alternatives, Public-key infrastructure (PKI) vs (Pretty Good Privacy) GPG, and how the idea of trust fits into the picture. He also points out an unfortunate fact when it comes to the initial adoption of package signing methods - people are lazy (and cheap). They want to get things done and not have extra steps. Signing their packages would be one of these steps. He suggests an alternative, though, using double signatures to verify the integrity and validity of its contents. He also talks about the role that metadata plays in the overall package ecosystem and how signing it as well could be part of the solution.