Why Git Logs Alone Cannot Prove Code Authorship or Priority in Disputes

Git commit history may appear to be a reliable record of who wrote code and when, but its timestamps and authorship fields can be freely rewritten using built-in commands like git commit --date and git filter-repo. Force-pushing can erase remote history entirely, and anyone with write access to a repository can alter the shared record after the fact. GPG-signed commits confirm content integrity but do not provide an independently verified timestamp, leaving the 'when' question unresolved. To establish legally credible proof of priority, developers need an independent third-party timestamp — such as an RFC 3161 Time-Stamping Authority — that cryptographically anchors a content hash to a specific moment in time. Maintaining such external records alongside a git repository is recommended as a precaution for codebases involved in commercial, IP-sensitive, or co-founded projects.