7 ms·

Well.. It will change some aspects of our world. Particularly financial assets at first, but increasingly it will play a role in any peer to peer exchange requi

Well.. It will change some aspects of our world. Particularly financial assets at first, but increasingly it will play a role in any peer to peer exchange requiring trust. Simple past examples are systems like OpenPGP that bind public keys to owners. Programmable blockchains allow generalized applications requiring decentralized trust. A good example of a use of blockchain outside of financial assets is in trust management of vehicular networks. In order for vehicles to communicate amongst each other, they need to trust that the messages they are receiving are authentic using a decentralized consensus mechanism and some sort of Bayesian Inference Model. So in short, it is an extension of the internet (trust layer) and it will change the world. So I don't think that's nonsense to say, but I can see how these claims would appear to be exaggerated to someone with limited exposure to Bitcoin and other cryptocurrencies.

Moodles 8y ago
I have a PhD in cryptography. Please be precise. Exactly what problem will blockchain solve for vehicles? You can't just hand wave and say stuff like "decentralized trust management" and expect us to nod along.
- easymodex 8y ago
  Trust and transparency.
  - Moodles 8y ago
    Are you capable of being precise?
- the_snooze 8y ago
  Yeah, I'm quite skeptical of it as well. If I'm being really charitable to it, then it's a way to synchronize data between parties without relying on a trusted intermediary. That said, it's unclear what practical value that has outside of purely digital applications like cryptocurrency. When you roll it into things in the real world (e.g., supply chains, health records, etc.) then you necessarily have to trust the data sources and sensors, at which point what good is a blockchain?
  - prostoalex 8y ago
    > it's a way to synchronize data between parties without relying on a trusted intermediary At the expense of time. So most real-world use cases (securities trading, vehicular networks, payments) fail when you introduce a 10-minute delay required for distributed confirmation. For time-insensitive examples you've provided - supply chain and health records - the use cases work better, but who will dedicate the resources and mine the blocks to ensure that specific blockchain's survival?
  - easymodex 8y ago
    Say you initiate a contract to sell a yacht for 1 million $. You and your buyer go to a notary where all 3 of you sign the contract and all the proper procedures. You give the buyer the yacht and he says he will transfer you the money tomorrow. Meanwhile the buyer and the notary strike a shady deal to screw you over and make new contracts that say you sold it for 1k$. It's 2 against 1 and you will lose a costly court battle and your yacht and so on. Solution: blockchain smart contracts where code is law, more secure, trustworthy and transparent than any individual, bank, government or company.
    - Moodles 8y ago
      You are trying to solve a problem with a blockchain that does not exist. Also, exactly how does your blockchain even know "this yacht now belongs to this person"?
      - tom_ 8y ago
        It doesn't. You go to court like normal people.
      - the_snooze 8y ago
        Exactly. How does the real world's state get accurately put into a blockchain? My big beef with all the blockchain hype is that this doesn't seem to be addressed. They say "trustless" and "secure" and "transparent" all the time, but those assurances only exist within the very limited confines of the data structure itself. As soon as you hook it into real-world data, then those assurances only guarantee that fraud is accurately carried out.
- gibsons77 8y ago
  This is the example I was referring to: https://ieeexplore.ieee.org/document/8358773 https://ieeexplore.ieee.org/document/8358773. The problem is one where there are multiple vehicles, from different manufacturers, that must communicate with each other in real time (say at an intersection) and must make decisions based on messages being relayed to them. This is easier if they are all following the same protocol.
  - Moodles 8y ago
    There is no need to have a database replicated everywhere across a network and for all nodes in the network to be constantly engaging in a consensus protocol to agree upon the state on the ledger for some cars to communicate. Almost always a blockchain is (i) useless or (ii) something kinda vaguely like Satoshi's blockchain but really more like Git.
    - gibsons77 8y ago
      I agree for this particular case, which is why I think a DAG with local consensus (something like IOTA) is more applicable for this application.
      - Moodles 8y ago
        I think DAGs are possibly even more useless.
        gibsons77 8y ago
        And you're of course free to have your own opinion. I'm not as quick to dismiss them simply because I acknowledge that new technologies have historically been ridiculed by experts at least initially. But healthy skepticism is always warranted.
    - yarrel 8y ago
      There is an important qualifier that people keep forgetting. You wouldn't need such a system for cars to communicate in the presence of authority or in the absence of value. The former is the case for Lyft or Uber, the latter is the case if we have an infinite supply of cars. But if one wishes to have peer-to-peer value (and cars ain't cheap) without a central authority (and Uber is evil) a proof-of-work blockchain is better for that than Git or a server run by some guy is. There may of course be superior social or technical forms for this use case. But once you have added the qualifier that the system should be decentralised (and for everyone making a career out of pretending not to understand what this word means: I mean here that there should be no central point of control at the point of transaction) a blockchain may make more sense than some of the alternatives.
- proxylittle 8y ago
  Is it just me or do the replies I'm seeing come across condescending and unsubstantial? I'm also missing why your PhD in cryptography is any important for the sake of the argument. We are not you in regards to your last remark by the way: "...expect us to nod along". But since you are looking for a good argument to support your confirmation bias, blockchain itself doesn't solve anything. It's just a data structure and a tool. The problem solving happens in the bigger picture, e.g. "decentralised trust management". But let me ask you this: exactly what problem will a database/tree/file solve for vehicles or currencies? We can agree upon that what you are asking and looking for can't be answered or will get a reply similar to: we don't have that problem. You may have asked the wrong question though. Let me be more precise and create a problem that doesn't exist but for programming purposes I want these requirements: many users should be able to read a (hardly) modifiable data structure that gets more resilient the more use it and that is a singleton who everybody has access to (call it decentralised if you will). Blockchain sounds like a perfect fit doesn't it? Now, when we replace the data structure keyword with OS and resiliency with speed, we can agree upon that this sounds like a decentralised operating system (Ethereum or whatnot). Don't get me wrong. I don't see any problems that need to be solved with blockchain right now either. But clearly there is a trend in cryptocurrencies and decentralisation that seems to be important to a lot of people. There are tons of problems that need solving: trust misuse, censorships, privacy issues, advertising and so on. That there is a need for a change is obvious. That this change started with blockchain technology is good. I'm also sure cryptography is important to you too. Why not embrace an emerging technology that benefit your field of study?
- abraham_lincoln 8y ago
  Service records for the life of the car. Vehicle purchasing/financing paperwork. Inspection tracking.
this_user 8y ago
A blockchain is just a type of data structure. I have yet to see any use case, outside of building crypto currencies, that could not be realised without it. The problem is not that the technology did not exist before, the problem is that people and organisations were slow or unwilling to adopt it. But that is not the type of issue that will be solved by introducing new technology, and almost all blockchain advocates seem to completely oblivious to these dynamics of human behaviour.
- sparkzilla 8y ago
  My company aims to convert all the world's news into data. Please tell me another technology that will allow us to build a decentralised, failure-tolerant, censorship- and tamper-resistant archive of that data, that allows anyone to add data, and have it verified without a central authority, and that anyone can use to create news applications.
  - bloomer 8y ago
    So you are building a write-only editor-less Wikipedia? Not sure how blockchain is related.
  - passiveincomelg 8y ago
    verified how?
    - the_snooze 8y ago
      And what exactly are you verifying?
      - sparkzilla 8y ago
        In its most basic form, we verify that data extracted from news articles matches what has been reported. So, when we extract the data "Trump, Speech, Alabama, Immigration" from an article, then it has to match the reporting in that original source, which may have included a sentence like, "Trump gives a speech in Alabama about immigration". To avoid the verification process being gamed we split up the data and send pieces to random people across the across the network. So, someone may be asked "Is this article about Trump?" and the next person may be asked "Which state is this sentence about?". They may not even see the whole original article.
justicezyx 8y ago
The logical reasoning is full of gap and holes that I cannot bother to rebuttal, because I am afraid of wasting my time. But I think Block chain can succeed. It matters less that it works, as long as the rich and powerful believe it can help then sustain their status.
vec 8y ago
> Programmable blockchains allow generalized applications requiring decentralized trust. Yeah, they don't really though. They allow a few extremely specific applications requiring decentralized trust. The trust guarantees only hold if no single party can, even momentarily, control more hashing power than was collectively used to generate the last X blocks, where X is number of updates made since the data you want to tamper with was inserted. To put it in concrete terms, pretend we have a blockchain for publishing PGP keys, and that your public key is 10 blocks down in the chain. If I want to maliciously replace your key with one of my own then all I need to do is rent a few dozen servers off of AWS for a day or two and use them to generate a modified chain that has my key instead of yours in the 11th block down and then rehash all ten blocks spending slightly more compute power each time than the original committers did. The network will recognize my fork as the authoritative one because it's got more proof of work. That's expensive, but it's certainly not infeasible. This trust mechanism works out for cryptocurrencies because their only value is monetary. That means that people are incentivized to set up mining rigs to spend a lot of real resources on mining because they automatically get compensated. It also means that there's a bounded maximum amount of effort that a rational actor will spend to tamper with the chain, because there's a finite limit on the available profit to be gained. Neither of these are true for PGP keys. Publishing a secure update to a PGP key database is not, in and of itself, a profit generating enterprise, meaning fewer miners and far less resources spent per mining rig. And the potential upside of successfully tampering with the right key is enormous. The actual mechanism which produces the security guarantees in blockchains isn't cryptographic, it's economic. Tampering with a cryptocurrency's blockchain isn't actually impossible, or even difficult, it's just by definition more expensive than it's worth. When you try and move to an application other than financial assets the economics break down, the security guarantees go out the window, and all you're left with is an extremely inefficient git clone.
- neospice 8y ago
  Please forgive my ignorance if I’m missing something obvious but in your PGP public key tampering example, wouldn’t this attack be ineffective against a blockchain that is stored in multiple peers. I.E your hashes wouldn’t match those of the peer copies of the blockchain?
0xfeba 8y ago
> they need to trust that the messages they are receiving are authentic using a decentralized consensus mechanism and some sort of Bayesian Inference Model. Or, since manufacturing an automobile is already centralized just use existing PKI.

Moodles 8y ago

I have a PhD in cryptography. Please be precise. Exactly what problem will blockchain solve for vehicles? You can't just hand wave and say stuff like "decentralized trust management" and expect us to nod along.

easymodex 8y ago
Trust and transparency.
- Moodles 8y ago
  Are you capable of being precise?
the_snooze 8y ago
Yeah, I'm quite skeptical of it as well. If I'm being really charitable to it, then it's a way to synchronize data between parties without relying on a trusted intermediary. That said, it's unclear what practical value that has outside of purely digital applications like cryptocurrency. When you roll it into things in the real world (e.g., supply chains, health records, etc.) then you necessarily have to trust the data sources and sensors, at which point what good is a blockchain?
- prostoalex 8y ago
  > it's a way to synchronize data between parties without relying on a trusted intermediary At the expense of time. So most real-world use cases (securities trading, vehicular networks, payments) fail when you introduce a 10-minute delay required for distributed confirmation. For time-insensitive examples you've provided - supply chain and health records - the use cases work better, but who will dedicate the resources and mine the blocks to ensure that specific blockchain's survival?
- easymodex 8y ago
  Say you initiate a contract to sell a yacht for 1 million $. You and your buyer go to a notary where all 3 of you sign the contract and all the proper procedures. You give the buyer the yacht and he says he will transfer you the money tomorrow. Meanwhile the buyer and the notary strike a shady deal to screw you over and make new contracts that say you sold it for 1k$. It's 2 against 1 and you will lose a costly court battle and your yacht and so on. Solution: blockchain smart contracts where code is law, more secure, trustworthy and transparent than any individual, bank, government or company.
  - Moodles 8y ago
    You are trying to solve a problem with a blockchain that does not exist. Also, exactly how does your blockchain even know "this yacht now belongs to this person"?
    - tom_ 8y ago
      It doesn't. You go to court like normal people.
    - the_snooze 8y ago
      Exactly. How does the real world's state get accurately put into a blockchain? My big beef with all the blockchain hype is that this doesn't seem to be addressed. They say "trustless" and "secure" and "transparent" all the time, but those assurances only exist within the very limited confines of the data structure itself. As soon as you hook it into real-world data, then those assurances only guarantee that fraud is accurately carried out.
gibsons77 8y ago
This is the example I was referring to: https://ieeexplore.ieee.org/document/8358773 https://ieeexplore.ieee.org/document/8358773. The problem is one where there are multiple vehicles, from different manufacturers, that must communicate with each other in real time (say at an intersection) and must make decisions based on messages being relayed to them. This is easier if they are all following the same protocol.
- Moodles 8y ago
  There is no need to have a database replicated everywhere across a network and for all nodes in the network to be constantly engaging in a consensus protocol to agree upon the state on the ledger for some cars to communicate. Almost always a blockchain is (i) useless or (ii) something kinda vaguely like Satoshi's blockchain but really more like Git.
  - gibsons77 8y ago
    I agree for this particular case, which is why I think a DAG with local consensus (something like IOTA) is more applicable for this application.
    - Moodles 8y ago
      I think DAGs are possibly even more useless.
      - gibsons77 8y ago
        And you're of course free to have your own opinion. I'm not as quick to dismiss them simply because I acknowledge that new technologies have historically been ridiculed by experts at least initially. But healthy skepticism is always warranted.
  - yarrel 8y ago
    There is an important qualifier that people keep forgetting. You wouldn't need such a system for cars to communicate in the presence of authority or in the absence of value. The former is the case for Lyft or Uber, the latter is the case if we have an infinite supply of cars. But if one wishes to have peer-to-peer value (and cars ain't cheap) without a central authority (and Uber is evil) a proof-of-work blockchain is better for that than Git or a server run by some guy is. There may of course be superior social or technical forms for this use case. But once you have added the qualifier that the system should be decentralised (and for everyone making a career out of pretending not to understand what this word means: I mean here that there should be no central point of control at the point of transaction) a blockchain may make more sense than some of the alternatives.
proxylittle 8y ago
Is it just me or do the replies I'm seeing come across condescending and unsubstantial? I'm also missing why your PhD in cryptography is any important for the sake of the argument. We are not you in regards to your last remark by the way: "...expect us to nod along". But since you are looking for a good argument to support your confirmation bias, blockchain itself doesn't solve anything. It's just a data structure and a tool. The problem solving happens in the bigger picture, e.g. "decentralised trust management". But let me ask you this: exactly what problem will a database/tree/file solve for vehicles or currencies? We can agree upon that what you are asking and looking for can't be answered or will get a reply similar to: we don't have that problem. You may have asked the wrong question though. Let me be more precise and create a problem that doesn't exist but for programming purposes I want these requirements: many users should be able to read a (hardly) modifiable data structure that gets more resilient the more use it and that is a singleton who everybody has access to (call it decentralised if you will). Blockchain sounds like a perfect fit doesn't it? Now, when we replace the data structure keyword with OS and resiliency with speed, we can agree upon that this sounds like a decentralised operating system (Ethereum or whatnot). Don't get me wrong. I don't see any problems that need to be solved with blockchain right now either. But clearly there is a trend in cryptocurrencies and decentralisation that seems to be important to a lot of people. There are tons of problems that need solving: trust misuse, censorships, privacy issues, advertising and so on. That there is a need for a change is obvious. That this change started with blockchain technology is good. I'm also sure cryptography is important to you too. Why not embrace an emerging technology that benefit your field of study?
abraham_lincoln 8y ago
Service records for the life of the car. Vehicle purchasing/financing paperwork. Inspection tracking.

this_user 8y ago

A blockchain is just a type of data structure. I have yet to see any use case, outside of building crypto currencies, that could not be realised without it. The problem is not that the technology did not exist before, the problem is that people and organisations were slow or unwilling to adopt it. But that is not the type of issue that will be solved by introducing new technology, and almost all blockchain advocates seem to completely oblivious to these dynamics of human behaviour.

sparkzilla 8y ago
My company aims to convert all the world's news into data. Please tell me another technology that will allow us to build a decentralised, failure-tolerant, censorship- and tamper-resistant archive of that data, that allows anyone to add data, and have it verified without a central authority, and that anyone can use to create news applications.
- bloomer 8y ago
  So you are building a write-only editor-less Wikipedia? Not sure how blockchain is related.
- passiveincomelg 8y ago
  verified how?
  - the_snooze 8y ago
    And what exactly are you verifying?
    - sparkzilla 8y ago
      In its most basic form, we verify that data extracted from news articles matches what has been reported. So, when we extract the data "Trump, Speech, Alabama, Immigration" from an article, then it has to match the reporting in that original source, which may have included a sentence like, "Trump gives a speech in Alabama about immigration". To avoid the verification process being gamed we split up the data and send pieces to random people across the across the network. So, someone may be asked "Is this article about Trump?" and the next person may be asked "Which state is this sentence about?". They may not even see the whole original article.

justicezyx 8y ago

The logical reasoning is full of gap and holes that I cannot bother to rebuttal, because I am afraid of wasting my time. But I think Block chain can succeed. It matters less that it works, as long as the rich and powerful believe it can help then sustain their status.

vec 8y ago

> Programmable blockchains allow generalized applications requiring decentralized trust. Yeah, they don't really though. They allow a few extremely specific applications requiring decentralized trust. The trust guarantees only hold if no single party can, even momentarily, control more hashing power than was collectively used to generate the last X blocks, where X is number of updates made since the data you want to tamper with was inserted. To put it in concrete terms, pretend we have a blockchain for publishing PGP keys, and that your public key is 10 blocks down in the chain. If I want to maliciously replace your key with one of my own then all I need to do is rent a few dozen servers off of AWS for a day or two and use them to generate a modified chain that has my key instead of yours in the 11th block down and then rehash all ten blocks spending slightly more compute power each time than the original committers did. The network will recognize my fork as the authoritative one because it's got more proof of work. That's expensive, but it's certainly not infeasible. This trust mechanism works out for cryptocurrencies because their only value is monetary. That means that people are incentivized to set up mining rigs to spend a lot of real resources on mining because they automatically get compensated. It also means that there's a bounded maximum amount of effort that a rational actor will spend to tamper with the chain, because there's a finite limit on the available profit to be gained. Neither of these are true for PGP keys. Publishing a secure update to a PGP key database is not, in and of itself, a profit generating enterprise, meaning fewer miners and far less resources spent per mining rig. And the potential upside of successfully tampering with the right key is enormous. The actual mechanism which produces the security guarantees in blockchains isn't cryptographic, it's economic. Tampering with a cryptocurrency's blockchain isn't actually impossible, or even difficult, it's just by definition more expensive than it's worth. When you try and move to an application other than financial assets the economics break down, the security guarantees go out the window, and all you're left with is an extremely inefficient git clone.

neospice 8y ago
Please forgive my ignorance if I’m missing something obvious but in your PGP public key tampering example, wouldn’t this attack be ineffective against a blockchain that is stored in multiple peers. I.E your hashes wouldn’t match those of the peer copies of the blockchain?

0xfeba 8y ago

> they need to trust that the messages they are receiving are authentic using a decentralized consensus mechanism and some sort of Bayesian Inference Model. Or, since manufacturing an automobile is already centralized just use existing PKI.