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Comment by noxToken | Hacker News Reader

> blockchains (as in bitcoin) are about being completely decentralized and trustless. It's an "and" not an "or", if you remove one of these imperatives they're completely pointless.

You're completely right, but I want to point out something subtle that I almost missed. For something to be considered a blockchain, it does not have to be distributed (as you noted). There can be a centralized entity (Wal-Mart) controlling the blockchain, but like you said, a controlling entity takes away trust. Without trust, Wal-Mart can still verify any tampering, but the public would still have to trust that Wal-Mart is coming forward with any discrepancies.

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You're right but again, blockchain is not needed for that part either. Just have wallmart publish their signed database publicly at regular intervals this way if they cheat and try to modify existing records anybody with an old dump could prove that something weird happened (since the database is signed simply showing a conflicting entry with a valid signature would be enough to demonstrate that either Wall-Mart did something fishy or that they got compromised. You wouldn't have to trust the whistle blower).

>but the public would still have to trust that Wal-Mart is coming forward with any discrepancies.

The entire point of blockchain is trustless. Otherwise a walmart database would be fine.

Sure, but they could also prevent tampering by just running a database themselves and not providing APIs that allow data to be tampered with. If they want to be able to prove it for external auditors, create a write-only audit trail the same way banks have been doing it for decades.

Is Wal-Mart really the threat in this case? I thought the threat was farmers too cheap to give their workers restroom breaks. This system will catch those farmers, and limit the sale of their produce. Wal-Mart doesn't actually want to sell dangerous lettuce.

I didn't mean to say that Wal-Mart was a threat. If the data is held internally, then it's up to the public to trust Wal-Mart's data. This is more a comment about a blockchain being moot than calling Wal-Mart a bad actor, but I can see how it goes the other way as well.

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