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The most obvious and widespread use of the concept of block chains in my opinion is git. It’s quite literally a distributed, unforgeable crypto-ledger of chang

by atonse 5y ago

The most obvious and widespread use of the concept of block chains in my opinion is git. It’s quite literally a distributed, unforgeable crypto-ledger of changes to common codebases that can be edited by multiple untrusted parties (open source).

ralusek 5y ago
That's not a block chain, though. A distributed ledger is one thing. A block chain is a specific technology to implement a distributed ledger. A block chain is specifically a linked-list-esque data structure with immutability through some irreproducible "cost," e.g. proof of work, proof of stake, etc, which in turn serves as the mechanism for arriving at a distributed consensus. Git histories are fully mutable, and adding to the ledger is still controlled by gatekeepers. I guess you could argue that forks allow it to bypass gatekeepers, but it really just moves gatekeepers from one place to another.
- WorldMaker 5y ago
  Git histories are only as immutable as the signatures applied to them. There are plenty of git repositories that follow rebase only "linked-list" history policies and require commits to be signed and through distributed consensus agree on what is the most recent commit to next commit against to keep the history a straight line. On the other side, forks happen in block chains all the time and it is an illusion that a block chain is only ever a "linked-list". It's just as much of a DAG at a technical level. The "cost" mechanics create a marketplace distinction between forks (branches in the DAG) far more than any technical distinction between them can possibly exist.
- atonse 5y ago
  Well you cannot change a git history without completely changing the hashes. Which is similar to blockchain. I see it as similar to CBC in crypto, where the previous block’s value plays a huge role in the next block’s encrypted value. Change one and you change the entire chain after that “block”
leifg 5y ago
This is a good example of the debate about the definition of a blockchain. Undoubtedly git's implementation is very similar to current blockchains but it's missing a reward function (PoS, PoW). So I would argue it's not a blockchain because of that.
- jnwatson 5y ago
  If you expand the system-under-definition to all the git repositories for a particular project, the proof of work function is the social dynamics (via PR/review/email) of getting changes accepted by other repositories.
- WorldMaker 5y ago
  There are multiple reward functions that apply to git. One particular example is a lot of developers compete for Proof of Clout (PoC) and all the green they can light up in the GitHub activity graph.

by atonse 5y ago

ralusek 5y ago

That's not a block chain, though. A distributed ledger is one thing. A block chain is a specific technology to implement a distributed ledger. A block chain is specifically a linked-list-esque data structure with immutability through some irreproducible "cost," e.g. proof of work, proof of stake, etc, which in turn serves as the mechanism for arriving at a distributed consensus. Git histories are fully mutable, and adding to the ledger is still controlled by gatekeepers. I guess you could argue that forks allow it to bypass gatekeepers, but it really just moves gatekeepers from one place to another.

WorldMaker 5y ago
Git histories are only as immutable as the signatures applied to them. There are plenty of git repositories that follow rebase only "linked-list" history policies and require commits to be signed and through distributed consensus agree on what is the most recent commit to next commit against to keep the history a straight line. On the other side, forks happen in block chains all the time and it is an illusion that a block chain is only ever a "linked-list". It's just as much of a DAG at a technical level. The "cost" mechanics create a marketplace distinction between forks (branches in the DAG) far more than any technical distinction between them can possibly exist.
atonse 5y ago
Well you cannot change a git history without completely changing the hashes. Which is similar to blockchain. I see it as similar to CBC in crypto, where the previous block’s value plays a huge role in the next block’s encrypted value. Change one and you change the entire chain after that “block”

leifg 5y ago

This is a good example of the debate about the definition of a blockchain. Undoubtedly git's implementation is very similar to current blockchains but it's missing a reward function (PoS, PoW). So I would argue it's not a blockchain because of that.

jnwatson 5y ago
If you expand the system-under-definition to all the git repositories for a particular project, the proof of work function is the social dynamics (via PR/review/email) of getting changes accepted by other repositories.
WorldMaker 5y ago
There are multiple reward functions that apply to git. One particular example is a lot of developers compete for Proof of Clout (PoC) and all the green they can light up in the GitHub activity graph.