Git is a blockchain | Hacker News Reader

Git is a blockchain

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13 pointsSwizec6 comments

Bitcoin is very much inspired by git; though in terms of immutability it's more similar to mercurial and subversion (git push -f)

Git accepts whatever timestamp a node chooses to add to a commit. This can cause interesting sorts in terms of chronological and topological sort orders.

Without an agreed-upon central git server there is not a canonical graph.

You can use GPG signatures with Git, but you need to provide your own keyserver and then there's still no way to enforce permissions (e.g. who can ALTER, UPDATE, or DELETE which files).

Git is a directed acyclic graph (DAG). Not a chain. Blockchains are chains to prevent double-spending (e.g. on a different fork).

Bitcoin was accepted by The Linux Foundation (Linus Torvalds wrote Git): https://lists.linuxfoundation.org/pipermail/bitcoin-dev/

It's always been a mix of inspiration in my mind:

- Torrent P2P file sharing.

- Git like data structure and protocol

- Immutability from functional programming

- Public key cryptography

It's not. This in particular is completely lacking:

> decentralized consensus?

Correct. While the post doesn't do the idea justice (and of course is a bit inaccurate), it still brings light to a good point, which is that blockchains may have some strong, legitimate use cases. We're still in the hype cycle of the technology, and the industry is rife with fraud. When the dust clears, I'm betting on seeing some important and successful projects emerge from the ashes.

What do you mean? Almost all git projects have a general consensus on what the code looks like. This concencensus is not immediate (eg. at any given point in time, different nodes may have a different view of the repository), but over time nodes tend to converge on a single "true" history. When this does not happen, we have what is called a "fork", which also occurs in blockchain based cryptocurrencies.

Put another way, every clone of the Linux repository agrees on what the kernel looked like at some point in the past (and all prior points which are recorded by git); however there is no central authority asserting this history.

But the consensus is determined by people, not git. Or, to put it another way, the lack of consensus algorithm in git is a feature, as it allows people to come to an agreement (or not) independent of the VCS.

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