Git Mark is a Block Trails Profile that anchors a Git history to Bitcoin by using each commit hash as the tweak that advances a trail, so the sequence of commits becomes a single-use-seal chain whose ordering and uniqueness are enforced by Bitcoin’s UTXO model. The Blocktrails verifier checks a git-mark trail against the chain, confirming that each marked commit was timestamped and is tamper-evident on Bitcoin — it proves the history’s immutability and temporal anchoring, not the correctness of the code itself. This gives a Bitcoin-secured provenance log for source repositories without storing any repository data on-chain.
Overview
- To mark a repository, the latest commit hash is folded into the controlling key and the trail’s head UTXO is spent to a new Taproot output. The Blocktrails verifier then walks the trail against the chain, confirming “each git mark, verified on-chain”. This proves the history is timestamped and tamper-evident — it does not assert that the code is correct, only that this history existed at this time and has not been silently rewritten.
Why it matters
- Git’s own hashes give integrity within a repository, but a maintainer can still rewrite or backdate history off-chain. Git Mark binds the history to Proof of Publication on Bitcoin, giving downstream consumers a trustless Provenance Tracking and Software Supply Chain Security signal without publishing source on-chain.