6 ms·

Do you need cryptographically signed, P2P distributed SQL statements that define order by referencing a hash of the previous statement block.

rocqua 9y ago
*And distributed consensus algorithm resistant to sybil attacks. That is presuming a blockchain needs something like proof of work to enforce them being append-only. One might argue semantics and claim that a blockchain only needs to be a 'chain of blocks' but I think most people expect some form of distributed consensus when something is called a 'blockchain'.
- vertex-four 9y ago
  Unfortunately, a pile of tech companies decided to start selling "blockchain" to banks which doesn't contain any distributed consensus system at all, never mind a Sybil-resistant one. As a result, people in the finance world and people surrounding that particular subset of the tech industry have a very warped idea of what a blockchain is. Under the definition often used in finance, all modern Linux machines are powered by blockchain, because journald uses hash-linked entries to provide evidence when log entries are manipulated.
  - simias 9y ago
    To be fair the term "blockchain" is too broad and generic to give it a very specific definition. I think that's a big reason for the hype, like "cloud computing". It's so vague that nobody really knows what it's about, if you actually decide to get technical you lose 95% of the audience as soon as you utter the words "cryptographic hash" or "public key cryptography". So you can just make any bold claims without going into details and still be sort of right. I can say something like "blockchain technology is going to be big for avocado cultivators to be able to audit production year after year". Does it make any sense? Who knows. But it keeps people going. And it's probably true too. Blockchain technology is here to stay. Cryptographic hashes, public key cryptography, merkle trees, hashcash, peer-to-peer networks, all that is here to stay. Of course, all that existed before the Blockchain, in the same way that servers existed before the "Cloud" but it doesn't matter, it's all about that sweet branding.
    - vertex-four 9y ago
      As a really quick hint, if somebody pushes blockchains as a solution for anything but cryptocurrency and managing cryptocurrency based on the state of other cryptocurrency, or a solution for Zooko's Triangle, they're selling a lie. EDIT: the reason for this is that if the chain ever needs to touch something that isn't entirely stored within the chain - for example, the number of avocados picked on a certain day - it needs a trusted oracle to tell it that. If you have a trusted oracle, you can trust that oracle to host a bog-standard SQL database and avoid this whole mess, unless your boss is breathing down your neck about using "blockchain" so your company can look cool and hip to its investors/clients.
      - rocqua 9y ago
        What about a registry of land ownership? That could be tracked fully on a blockchain with the added advantage of no longer needing to trust some centralized office to 1) correctly track ownership and 2) properly store their records. A similar idea exists for tracking ownership of domain names. There are other cases where you trust the oracle but want some form of non-equivocation. A nice example is a notary. In that case, just an SQL database doesn't suffice. Sometimes, something like a pgp-signed statement could work for that. If you want some more resilience against the claim 'that was signed with a fake key' you could mandate all signatures be published on an actual block-chain. This time-stamps them so you can see whether they happened before a key compromise, and allows the requirement that the counter-party audits the blockchain to ensure that no signatures are published that they did not know of. This audit would mean that signatures published with a compromised key would quickly be detected. This way, the records of the notary are publicaly checkable. You now only need to trust the notary at the time of publishing their signature on the blockchain (with some extra time to ensure they can't claim to not have audited yet).
        mythrwy 9y ago
        Public records does seem like a reasonable use case. Birth, death, marriage, ownership etc. Not sure it's a lot better than what we have now but it might be cheaper. (Or the reverse.)
- seanalltogether 9y ago
  Perhaps, I assumed that a lot of the "me too" blockchain investigations happening at large corporations never intend to use distributed consensus, they expect the blocks to be signed by trusted sources.

rocqua 9y ago

*And distributed consensus algorithm resistant to sybil attacks. That is presuming a blockchain needs something like proof of work to enforce them being append-only. One might argue semantics and claim that a blockchain only needs to be a 'chain of blocks' but I think most people expect some form of distributed consensus when something is called a 'blockchain'.

vertex-four 9y ago
Unfortunately, a pile of tech companies decided to start selling "blockchain" to banks which doesn't contain any distributed consensus system at all, never mind a Sybil-resistant one. As a result, people in the finance world and people surrounding that particular subset of the tech industry have a very warped idea of what a blockchain is. Under the definition often used in finance, all modern Linux machines are powered by blockchain, because journald uses hash-linked entries to provide evidence when log entries are manipulated.
- simias 9y ago
  To be fair the term "blockchain" is too broad and generic to give it a very specific definition. I think that's a big reason for the hype, like "cloud computing". It's so vague that nobody really knows what it's about, if you actually decide to get technical you lose 95% of the audience as soon as you utter the words "cryptographic hash" or "public key cryptography". So you can just make any bold claims without going into details and still be sort of right. I can say something like "blockchain technology is going to be big for avocado cultivators to be able to audit production year after year". Does it make any sense? Who knows. But it keeps people going. And it's probably true too. Blockchain technology is here to stay. Cryptographic hashes, public key cryptography, merkle trees, hashcash, peer-to-peer networks, all that is here to stay. Of course, all that existed before the Blockchain, in the same way that servers existed before the "Cloud" but it doesn't matter, it's all about that sweet branding.
  - vertex-four 9y ago
    As a really quick hint, if somebody pushes blockchains as a solution for anything but cryptocurrency and managing cryptocurrency based on the state of other cryptocurrency, or a solution for Zooko's Triangle, they're selling a lie. EDIT: the reason for this is that if the chain ever needs to touch something that isn't entirely stored within the chain - for example, the number of avocados picked on a certain day - it needs a trusted oracle to tell it that. If you have a trusted oracle, you can trust that oracle to host a bog-standard SQL database and avoid this whole mess, unless your boss is breathing down your neck about using "blockchain" so your company can look cool and hip to its investors/clients.
    - rocqua 9y ago
      What about a registry of land ownership? That could be tracked fully on a blockchain with the added advantage of no longer needing to trust some centralized office to 1) correctly track ownership and 2) properly store their records. A similar idea exists for tracking ownership of domain names. There are other cases where you trust the oracle but want some form of non-equivocation. A nice example is a notary. In that case, just an SQL database doesn't suffice. Sometimes, something like a pgp-signed statement could work for that. If you want some more resilience against the claim 'that was signed with a fake key' you could mandate all signatures be published on an actual block-chain. This time-stamps them so you can see whether they happened before a key compromise, and allows the requirement that the counter-party audits the blockchain to ensure that no signatures are published that they did not know of. This audit would mean that signatures published with a compromised key would quickly be detected. This way, the records of the notary are publicaly checkable. You now only need to trust the notary at the time of publishing their signature on the blockchain (with some extra time to ensure they can't claim to not have audited yet).
      - mythrwy 9y ago
        Public records does seem like a reasonable use case. Birth, death, marriage, ownership etc. Not sure it's a lot better than what we have now but it might be cheaper. (Or the reverse.)
seanalltogether 9y ago
Perhaps, I assumed that a lot of the "me too" blockchain investigations happening at large corporations never intend to use distributed consensus, they expect the blocks to be signed by trusted sources.