(Thanks for the gitchain link.) | decentralized ledger I'm not sure I quite understand. If the aim is to have a system where there is an immutable record of changes to a (set of) digital objects, then any content addressable based system, e.g. Mercurial, Git, CamlStore, would do the job. Taking Git as a most familiar system, the DAG of Git affords both 'attribution' and 'timeline' datum. Can the proverbial Uncle Joe or NYT go and change commit records in Github? Let's discuss "decentralized". (I'm on and off the net as you know but will be following up! :)]
No, but someone could at Github could, correct? Isn't the requisite for an immutable record the distribution of the consensus on the validity of the record? My interpretation of the decentralized ledger, is the distribution of not only the data on the ledger, but also the distribution of the consensus mechanism required for changes of the ledger.Can the proverbial Uncle Joe or NYT go and change commit records in Github?
The plan is not only for Gitchain to run across myriad machines, but for it to store some Git metadata–user names and permissions, for example–in a cryptographically verifiable format similar to the bitcoin blockchain. This would allow software developers to prove that their code hasn’t been tampered with–just one example of how the project could be expanded in new ways.
Github personnel can truncate records (as in remove certain commits past time t. They can not go and cherry pick a prior commit's content.). Having mirrors that periodically pull from Github would address that trivially. The consensus bit goes back to my earlier comment re Vector Clocks and the CAP matter posted today. Perfect consensus in the material world is impossible.