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There's nothing that ties a blockchain to proof of work. Proof of work just just one consensus protocol. For instance, JP Morgan's Quorum is working on Raft bas

by subway 9y ago

There's nothing that ties a blockchain to proof of work. Proof of work just just one consensus protocol. For instance, JP Morgan's Quorum is working on Raft based consensus. https://github.com/jpmorganchase/quorum/blob/master/raft/doc.md https://github.com/jpmorganchase/quorum/blob/master/raft/doc...

hudon 9y ago
The nodes are federated and you're still calling this a blockchain? What definition of the word "blockchain" are you using? Is this not more commonly called a "distributed database"?
- cbr 9y ago
  To me, "blockchain" implies the individual nodes don't trust each other, while "distributed database" does.
- derefr 9y ago
  A "blockchain", taken as a primitive, is essentially an append-only (geographically-)distributed database. Consider: a Starcraft 1v1 ladder match is, by this definition, synchronized using a "blockchain", whose participating nodes are the two players' computers and the auditing ladder-server instance. That's not a reductio ad absurdam; that's actually what you should be picturing when you say "blockchain" generally: participant nodes, an event stream chunked into blocks, and a consensus mechanism for validating blocks. Proof-of-work is just one consensus mechanism for blockchains. Mutually-agreed arbitration oracles (as above) is another. First-claim using a global hierarchy of signed-timestamping servers is a third. Etc.
subway 9y ago
Replying to myself since we hit max comment depth (probably an indicator it's time to move away from this thread anyway). but to address the sibling reply by hudon, yes, a blockchain is a form of a distributed database (maybe highly replicated data base is a better term since every node has the full working data set). The key trait of a blockchain is that each new entry cryptographically verifies all previous entries. At the end of the day, yes, a blockchain is a distributed db. It's a distributed db that never forgets.
- hudon 9y ago
  > The key trait of a blockchain is that each new entry cryptographically verifies all previous entries I see what you're saying. Basically: distributed database + signatures + merkle tree = blockchain. I usually use this definition: decentralized and sybil-resistant database + signatures + merkle tree = blockchain. So I think the key trait that turns a distributed database into a blockchain is not the merkle tree, but is its decentralized nature. Anyone can be a transaction validator and no one can prevent transaction validation.

by subway 9y ago

hudon 9y ago

The nodes are federated and you're still calling this a blockchain? What definition of the word "blockchain" are you using? Is this not more commonly called a "distributed database"?

cbr 9y ago
To me, "blockchain" implies the individual nodes don't trust each other, while "distributed database" does.
derefr 9y ago
A "blockchain", taken as a primitive, is essentially an append-only (geographically-)distributed database. Consider: a Starcraft 1v1 ladder match is, by this definition, synchronized using a "blockchain", whose participating nodes are the two players' computers and the auditing ladder-server instance. That's not a reductio ad absurdam; that's actually what you should be picturing when you say "blockchain" generally: participant nodes, an event stream chunked into blocks, and a consensus mechanism for validating blocks. Proof-of-work is just one consensus mechanism for blockchains. Mutually-agreed arbitration oracles (as above) is another. First-claim using a global hierarchy of signed-timestamping servers is a third. Etc.

subway 9y ago

Replying to myself since we hit max comment depth (probably an indicator it's time to move away from this thread anyway). but to address the sibling reply by hudon, yes, a blockchain is a form of a distributed database (maybe highly replicated data base is a better term since every node has the full working data set). The key trait of a blockchain is that each new entry cryptographically verifies all previous entries. At the end of the day, yes, a blockchain is a distributed db. It's a distributed db that never forgets.

hudon 9y ago
> The key trait of a blockchain is that each new entry cryptographically verifies all previous entries I see what you're saying. Basically: distributed database + signatures + merkle tree = blockchain. I usually use this definition: decentralized and sybil-resistant database + signatures + merkle tree = blockchain. So I think the key trait that turns a distributed database into a blockchain is not the merkle tree, but is its decentralized nature. Anyone can be a transaction validator and no one can prevent transaction validation.