A while ago I participated in security design for an open source foundation. (Security is not a specialty of mine, but I aspire to be competent enough for my role as a developer working in web dev and open source.) We attempted to design our processes to assure some level of defense against state-level threat actors despite assuming we could not keep them out of our network. The main goal was to ensure an audit trail in the event that our source repositories or release archives were compromised and changed.