A Git Horror Story: Repository Integrity With Signed Commits
Interesting solution, but is this really a problem? The only situations I can think this applies to are large-scale open-source projects with many maintainers, and even more people submitting patches. For closed-source projects without external patch submissions, this is really only avoids the security threat of someone sitting at your computer and committing malicious code to your repository, which (to me) doesn't sound like much of a threat. (At least, if that is a threat, rogue commits to your git repo are only one part of your problem, and door locks would probably be a better, more broadly beneficial solution than implementing this.)