- Ledger is a file in a Git repo
- Blocks are confirmed by committing them with a SHA1 with sufficiently many leading zeros (adjust a nonce in the commit msg until it fits)
- Some bot accepts all pull requests into the Github repo that are fast-forward and whose commits have sufficiently many leading 0s (possibly after confirming that the booking is valid ;)
We could call that... oh I don't know, DvcsCoin or so.