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I really don't like the idea that a blockchain is just a chain of objects that commit to eachother by hashing. That is not what anyone in the industry is referr

by Taek 7y ago

I really don't like the idea that a blockchain is just a chain of objects that commit to eachother by hashing. That is not what anyone in the industry is referring to when they say "blockchain". A blockchain is a trust minimizing, independent network which allows participants to interact with eachother such that: 1. Everybody knows who did what, in what order 2. Significant confidence exists that the order is fixed / finalized (git can't give you this) 3. There is no set of controlling parties that could reasonably be expected to change the rules of the system, even if they were all trying to work together. When someone says "blockchains are going to change the world", they are talking about the above three properties, not about the ability to commit to a thing that commits to other things.

chpmrc 7y ago
Well, that's the marketing interpretation of "blockchain", the same way the media use "hacker" nowadays to indicate anyone who breaches an information system. A blockchain is simply a data structure. In git you can achieve 1 by signing commits, 2 by simply comparing what you have with everyone else has (if the majority of the network wants the history to be changed it will change, no matter the technology), 3 can definitely be achieved even for cryptocurrencies (51% attack and the like). At the end of the day distributed trust literally means we all trust each other to do the right thing because, at the end, it's more cost effective and more beneficial for everyone. Directly from the Bitcoin whitepaper: "The incentive may help encourage nodes to stay honest. If a greedy attacker is able to assemble more CPU power than all the honest nodes, he would have to choose between using it to defraud people by stealing back his payments, or using it to generate new coins. He ought to find it more profitable to play by the rules, such rules that favour him with more new coins than everyone else combined, than to undermine the system and the validity of his own wealth."
detaro 7y ago
All the "private blockchain" things seem to not have 3. by design? (but their proponents typically are quite bad at providing clear explanations, so I might be misunderstanding what's going on there)

by Taek 7y ago

chpmrc 7y ago

Well, that's the marketing interpretation of "blockchain", the same way the media use "hacker" nowadays to indicate anyone who breaches an information system. A blockchain is simply a data structure. In git you can achieve 1 by signing commits, 2 by simply comparing what you have with everyone else has (if the majority of the network wants the history to be changed it will change, no matter the technology), 3 can definitely be achieved even for cryptocurrencies (51% attack and the like). At the end of the day distributed trust literally means we all trust each other to do the right thing because, at the end, it's more cost effective and more beneficial for everyone. Directly from the Bitcoin whitepaper: "The incentive may help encourage nodes to stay honest. If a greedy attacker is able to assemble more CPU power than all the honest nodes, he would have to choose between using it to defraud people by stealing back his payments, or using it to generate new coins. He ought to find it more profitable to play by the rules, such rules that favour him with more new coins than everyone else combined, than to undermine the system and the validity of his own wealth."

detaro 7y ago

All the "private blockchain" things seem to not have 3. by design? (but their proponents typically are quite bad at providing clear explanations, so I might be misunderstanding what's going on there)