5 ms·

Blockchains don’t have to be decentralized and you can undo a transaction by making a new transaction that reverses the changes.

7thaccount 2y ago
What's the point than?
- admax88qqq 2y ago
  Auditable history.
  - Legend2440 2y ago
    You don't need blockchain for that, you can just use git.
    - admax88qqq 2y ago
      Git is a blockchain
      - Legend2440 2y ago
        No; it's a hash tree. Blockchain is also a hash tree, but not all hash trees are blockchain. They've been around since the 70s.
        admax88qqq 2y ago
        They’re functionally equivalent these days. Blockchain has become marketing speak mostly. But if you squint a little. The history of a git branch sure looks a lot like a blockchain (or vice versa). You have a ledger of records (commits), that are append only, and each commit contains a merkle or hash tree (git tree object) So yeah git is basically a blockchain.
        talldayo 2y ago
        I have to squint pretty hard to convince myself. Git itself really only covers the auditing part, which any static service will do by virtue of storing data. Git repos aren't decentralized, they rely entirely on external software like GPG and SSH to enforce identity and have no native consensus mechanism. They also don't protect from erasing transactional history which is kinda seen as the cardinal sin of ledger-based economics. If you wanted to be reductive you could try to argue that all linked lists or hashmaps are a blockchain once compiled. I think that's silly, bordering on revisionism. Git wasn't programmed as a Blockchain, and Blockchains weren't intended to resemble Git.
        admax88qqq 2y ago
        > Git repos aren’t decentralized Sure they are. Git is one of the pioneering “distributed” version control systems. Every clone of a git repo is a complete copy. Sounds pretty decentralized to me. Git’s native consensus mechanism is to defer to humans and record their decisions as merge commits. I agree git natively doesn’t protect against erasing history. Although rebase is discouraged and any one node can’t forcibly erase history from every other node.
        talldayo 2y ago
        > Every clone of a git repo is a complete copy. Sounds pretty decentralized to me. Every clone of a DNS lookup table is a complete copy too. That doesn't change the fact that DNS is one of the least decentralized technologies being developed and propagated today.
        admax88qqq 2y ago
        That’s more a question of how you hold it. You can keep your own local DNS list or run one for you and your friends (OpenNIC) But for DNS it’s typically most convenience if everyone agrees on who google.com is.
      - goalonetwo 2y ago
        lol
  - 7thaccount 2y ago
    Databases do that just fine.
solardev 2y ago
Without decentralization, doesn't that mean you don't even need a 51% attack... the central authority can just rewrite the ledger history at will, the same as any database or git history?
- throwthrowuknow 2y ago
  It’s a government agency, I don’t think they’re doing this with the intent of giving up that authority.
  - solardev 2y ago
    So what does the blockchain actually accomplish...?
    - ceejayoz 2y ago
      Nothing. As is tradition.
    - throwthrowuknow 2y ago
      Just a different way of having an auditable and verifiable transaction history. Maybe it’s easier to share the blockchain than it would be to share copies of the database? They could be leveraging the existing tools for copying and verifying it, perhaps one of the requirements is that end users or dealers need to have access to a local copy that they can use to check the ownership history of a vehicle before a purchase? Everyone loves to hate on anything blockchain but it’s a useful data structure.
      - solardev 2y ago
        I don't think this really makes sense...? A blockchain is awesome for decentralized verification of a shared ledger, but without that, it's no different than a line by line history of writes in a text file. If a dealer has a local copy of the ledger but isn't really part of the blockchain consensus, it's no different than having a read only history in any other structure. It doesn't matter what format you store it in, it's more a question of who can rewrite history. If the central authority can do so at will and nobody can disagree with them, it nullifies the benefits of using a blockchain. The dealer can say "it doesn't match our records", sure, but they can say that no matter if a blockchain or a bunch of CSVs are used. If the DMV then says sorry, our records are the only authoritative ones, please overwrite yours... then we're right back where we started. I don't think people hate blockchains as a data structure, but as misapplied snake oil that doesn't solve the underlying problems. This doesn't create a real audit trail as much as the illusion of one. A proper audit trail would require the authoritative history to reside elsewhere, in some independent third party that the DMV cannot unilaterally overwrite.

7thaccount 2y ago

What's the point than?

admax88qqq 2y ago
Auditable history.
- Legend2440 2y ago
  You don't need blockchain for that, you can just use git.
  - admax88qqq 2y ago
    Git is a blockchain
    - Legend2440 2y ago
      No; it's a hash tree. Blockchain is also a hash tree, but not all hash trees are blockchain. They've been around since the 70s.
      - admax88qqq 2y ago
        They’re functionally equivalent these days. Blockchain has become marketing speak mostly. But if you squint a little. The history of a git branch sure looks a lot like a blockchain (or vice versa). You have a ledger of records (commits), that are append only, and each commit contains a merkle or hash tree (git tree object) So yeah git is basically a blockchain.
        talldayo 2y ago
        I have to squint pretty hard to convince myself. Git itself really only covers the auditing part, which any static service will do by virtue of storing data. Git repos aren't decentralized, they rely entirely on external software like GPG and SSH to enforce identity and have no native consensus mechanism. They also don't protect from erasing transactional history which is kinda seen as the cardinal sin of ledger-based economics. If you wanted to be reductive you could try to argue that all linked lists or hashmaps are a blockchain once compiled. I think that's silly, bordering on revisionism. Git wasn't programmed as a Blockchain, and Blockchains weren't intended to resemble Git.
        admax88qqq 2y ago
        > Git repos aren’t decentralized Sure they are. Git is one of the pioneering “distributed” version control systems. Every clone of a git repo is a complete copy. Sounds pretty decentralized to me. Git’s native consensus mechanism is to defer to humans and record their decisions as merge commits. I agree git natively doesn’t protect against erasing history. Although rebase is discouraged and any one node can’t forcibly erase history from every other node.
        talldayo 2y ago
        > Every clone of a git repo is a complete copy. Sounds pretty decentralized to me. Every clone of a DNS lookup table is a complete copy too. That doesn't change the fact that DNS is one of the least decentralized technologies being developed and propagated today.
        admax88qqq 2y ago
        That’s more a question of how you hold it. You can keep your own local DNS list or run one for you and your friends (OpenNIC) But for DNS it’s typically most convenience if everyone agrees on who google.com is.
    - goalonetwo 2y ago
      lol
- 7thaccount 2y ago
  Databases do that just fine.

solardev 2y ago

Without decentralization, doesn't that mean you don't even need a 51% attack... the central authority can just rewrite the ledger history at will, the same as any database or git history?

throwthrowuknow 2y ago
It’s a government agency, I don’t think they’re doing this with the intent of giving up that authority.
- solardev 2y ago
  So what does the blockchain actually accomplish...?
  - ceejayoz 2y ago
    Nothing. As is tradition.
  - throwthrowuknow 2y ago
    Just a different way of having an auditable and verifiable transaction history. Maybe it’s easier to share the blockchain than it would be to share copies of the database? They could be leveraging the existing tools for copying and verifying it, perhaps one of the requirements is that end users or dealers need to have access to a local copy that they can use to check the ownership history of a vehicle before a purchase? Everyone loves to hate on anything blockchain but it’s a useful data structure.
    - solardev 2y ago
      I don't think this really makes sense...? A blockchain is awesome for decentralized verification of a shared ledger, but without that, it's no different than a line by line history of writes in a text file. If a dealer has a local copy of the ledger but isn't really part of the blockchain consensus, it's no different than having a read only history in any other structure. It doesn't matter what format you store it in, it's more a question of who can rewrite history. If the central authority can do so at will and nobody can disagree with them, it nullifies the benefits of using a blockchain. The dealer can say "it doesn't match our records", sure, but they can say that no matter if a blockchain or a bunch of CSVs are used. If the DMV then says sorry, our records are the only authoritative ones, please overwrite yours... then we're right back where we started. I don't think people hate blockchains as a data structure, but as misapplied snake oil that doesn't solve the underlying problems. This doesn't create a real audit trail as much as the illusion of one. A proper audit trail would require the authoritative history to reside elsewhere, in some independent third party that the DMV cannot unilaterally overwrite.