Is Git a Block Chain?

#1

Post by argon » Sat, Apr 25, 2015, 1:49 AM UTC

Re: Is Git a Block Chain?

#2

Post by wmf » Sat, Apr 25, 2015, 2:21 AM UTC

Consensus seems like an essential property that distinguishes a blockchain from a Merkle tree, and git does not provide consensus.

Re: Is Git a Block Chain?

#3

Post by sadgit » Sat, Apr 25, 2015, 2:31 AM UTC

No, its not. Its just a chain. There's no block. The block in a blockchain is everything to do with distributed / trustless conscensus.

Re: Is Git a Block Chain?

#4

Post by jscottmiller » Sat, Apr 25, 2015, 2:31 AM UTC

"Blockchain" is generally used to refer to systems that either 1) use the sequence of blocks to model changes in custodianship or 2) (more generally) enforce a set of rules governing the correctness of a given block.

That is, a block in the bitcoin blockchain is valid not only if its hash matches what one would expect given the included transactions, but that those transactions adhere to the rules of bitcoin. (No double-spends, no dust transactions, etc).

While there are data structures in a git commit that must be present and/or follow a particular set of semantics, git does not enforce anything about the _contents_ of those commits.

Another key distinction: blockchains seek consensus, whereas divergent forks in git repos are by design.

EDIT: I should probably not distinguish too much between consensus and rule enforcement, as those two are obviously intertwined. :)

Re: Is Git a Block Chain?

#5

Post by joeframbach » Sat, Apr 25, 2015, 2:32 AM UTC

Related is the Gitcoin mining challenge from Stripe's Capture The Flag 3.

Here's a writeup: https://github.com/ctfs/write-ups-2014/tree/master/stripe-ct...

A Gitcoin miner updates the ledger (a text file in the repo), and "mines" the next-smaller hash.

It doesn't have consensus, but it does give a neat programming challenge.

Re: Is Git a Block Chain?

#6

Post by nebulous1 » Sat, Apr 25, 2015, 2:44 AM UTC

Not sure I get it. Appears to be technically correct assuming we view the term "block chain" as a basic combination of the words as opposed to a term of art, but without the PoW it seems to be missing the point.

Re: Is Git a Block Chain?

#7

Post by ntonozzi » Sat, Apr 25, 2015, 3:06 AM UTC

Both git repositories and bitcoin are specialized Merkle trees. Merkle trees are incredibly useful and general; they are used in many kinds of verification, especially of large chunks of data.

http://en.wikipedia.org/wiki/Merkle_tree

Re: Is Git a Block Chain?

#8

Post by [deleted] » Sat, Apr 25, 2015, 3:28 AM UTC

[deleted]

Re: Is Git a Block Chain?

#9

Post by northben » Sat, Apr 25, 2015, 3:36 AM UTC

sadgit wrote: post #3

No, its not. Its just a chain. There's no block. The block in a blockchain is everything to do with distributed / trustless conscensus.

Imagine how cool it would be if I could share a guid for my repo - and then your bit client (let's call it gitcoin, or maybe just bit) can fetch new commits from a distributed block chain (essentially the git log). Github is no longer an intermediary or a single point of failure. Private repo? Don't share the guid.

Re: Is Git a Block Chain?

#10

Post by Buge » Sat, Apr 25, 2015, 3:51 AM UTC

northben wrote: post #9

sadgit wrote: post #3

No, its not. Its just a chain. There's no block. The block in a blockchain is everything to do with distributed / trustless conscensus.

Imagine how cool it would be if I could share a guid for my repo - and then your bit client (let's call it gitcoin, or maybe just bit) can fetch new commits from a distributed block chain (essentially the git log). Github is no longer an intermediary or a single point of failure. Private repo? Don't share the guid.

If it's distributed then I don't think private repos would be possible, unless they were encrypted.