7 ms·

Blockchain in a Nutshell

43 points by blopeur 4y ago

dandanua 4y ago
It is the technology behind the success of ... Here, I saved you a click.
- tomschwiha 4y ago
  Do you usually first click on the article or directly jump into the comments? I tend to do both at the same time.
  - dandanua 4y ago
    Cryptosphere is a cesspool full of lies and manipulation. People who understand this will read the comments first, I guess.
  - rvz 4y ago
    I assume that for each post on this site, everyone has read the article (and in this case, this paper) before jumping into the comments section to discuss what they have just read. It seems the person you have just replied to has already admitted that they have read as far as just one sentence before rushing here in minutes later. Perhaps they do this with every article they see. There are those who are unable to read beyond the headlines or the first paragraph and react here immediately. No wonder they are manipulated all the time these days as evident in their own reply below. Is that what it has gotten to on this site?
  - djvdq 4y ago
    I usually start with comments. Only after that, if majority of the comments are not "this article is false and bad" I open the article. Is it good or bad? No idea.
jpgvm 4y ago
Blockchain as it stands still remains primarily an interesting solution looking for a killer problem. I think what it really needs is to find a problem that it's objectively better than the non-blockchain alternative. As a store of value, currency or payment network it's yet to be able to prove that. For more interesting applications, smart contracts etc the networks themselves are still struggling to find ways to keep transactions/operating costs in line with value. Even those more complex cases aren't yet objectively superior to other technology choices. I think we will find use-cases for byzantine-proof distributed ledger but nothing has yet been compelling enough to supplant other options.
- medo-bear 4y ago
  this is a very original and novel insight. thank you
- arcticbull 4y ago
  It's a lot like quantum computing. It's hip, and exciting, and easy to raise money for. But the set of algorithms that are better implemented by extant quantum computers than classical systems is, last I checked, the empty set.
- k__ 4y ago
  The killer problem is fake news. I don't think blockchains are the only or even best solutions to fake news, but the ecosystem build around them uses public-key cryptography for everything. A world where every piece of information is signed, could be a harsh blow for fake news. It's what PGP always wanted to go mainstream. Maybe, the money behind it (reasonable or not) is finally enough to motivate the mainstream.
  - vesinisa 4y ago
    Ugh? Yes, fake news is about a trust problem - people trusting sources which spread nefariously incorrect or distorted views. But no, public key cryptography or blockchain does not solve this problem. I am not sure what do you even propose exactly but think for a moment what differentiates a "real news" and "fake news" source from each other, and you are back to square one. People who read fake news already now choose to trust and subscribe to their reporting.
  - NikolaNovak 4y ago
    I'd love to hear more. A) fake news is hard to define and agree upon B) different people will have different criteria definition and Venn diagrams of fake news C1) many people and organizations start and distribute fake news knowing them to be such C2) many people and organizations start or propagate fake news while earnestly believing them Can you help understand how block chain or public key cryptography will help or address anything relating to fake news? Is there an underlying assumption that ascertaining identity will help? Because from my perspective majority of fake news are created and propagated by readily and eagerly identifiable people, whether potus or my cousin on Facebook and anything in between. In other words, today already I pretty much know who is relating any given piece of news. I may even know where or who originated them. It does not in the least solve the problem that my liberal and conservative, atheist and religious. Rich and poor, immigrant and local, technical and humanities etc neighbours have completely different parameters and selection of trust. Identifying the source helps not a bit with radically different selections of source. And then we get to "disagreeable" topics - how will block chain help those who fundamentally disagree on climate abortion religion economy foreign politics military basic income refugees healthcare rights etc. They will continue to pick and choose whatever our inherent bias is. There is this utopian notion that tech framework will solve a human problem.
_fizz_buzz_ 4y ago
> transact without having to second-guess trust and transparency Lots of people get scammed with crypto. Whatever web3 is solving, this ain’t it.
FabHK 4y ago
The article proclaims "the intermediaries" as the solution to the trust problem. That is incomplete in two ways: 1. Intermediaries are not the only solution to the trust problem, there are many many others. (See for example Bruce Schneider's Liars and Outliers, where he lists morality, reputation, institutions, security systems [1,2].) 2. Intermediaries don't only solve the problem of trust, but can also make things more efficient. If any two nodes need a connection, a graph needs O(N^2) edges. With a central intermediary, it only needs O(N) edges. [1,2] See https://www.schneier.com/books/liars-and-outliers https://www.schneier.com/books/liars-and-outliers, or https://www.wired.com/story/theres-no-good-reason-to-trust-blockchain-technology/ https://www.wired.com/story/theres-no-good-reason-to-trust-b...
wslh 4y ago
50 pages!
deleted 4y ago
[deleted]
mjburgess 4y ago
If you're trying to assess whether this is more propaganda, let me help: > Trust is the biggest bottleneck in realizing transactions. It is the biggest bottleneck in advancing the society. As a trust-less system, blockchain removes that bottleneck. Indeed, apparently trust in transactional system is our biggest problem. And indeed, apparently, blockchains provide that trust. here's me thinking its trust in social institutions which is our biggest problem, an issue made much worse by blockchain, which offers no systems of redress (perhaps the most significant benefit of institutions and trust).
- arcticbull 4y ago
  Trust in transactions isn't an issue at all. When was the last time you threw down your Visa card and worried about ... anything? They offer redress via chargebacks. You trust Visa, Visa trusts the merchants. Something goes wrong, call your bank. Ezpz. Now you may argue that you can't pay for your, uh, illegal or immoral material with a Visa card. That's a different matter. In my opinion, the government should recognize modern payments rails as critical infrastructure and require them to process all legal transactions without discrimination. A sort of payments net neutrality. [edit] You may also argue that merchant fees are "too high" - yeah they're high in America. They're 0.3% in Europe, because again, that's a job for regulation. They don't get card transaction rewards (because that's where the overwhelming majority of interchange goes) but that's the trade-off they've chosen to make. Replacing modern payment rails with magic beans that live in your computer solves literally nothing for the overwhelming majority of people, which indeed, is why the overwhelming majority of people never transact on-chain. They speculate on the sidelines from centralized, trusted exchanges. It's gambling on unregistered securities to most people.
  - trevelyan 4y ago
    If you read the whitepaper it flags (first paragraph) that the problem with payment systems that rely on trusted third parties like Visa is not that they don't work but that these parties are compelled to mediate. You may not mind yourself -- Visa is useful -- but adding this kind of closure isn't cost-free (look at Wikileaks) and the fundamental innovation in how to do this without introducing any trusted third parties is a big deal. With that said, I agree most of the new POS variants and DAGs are sneaking closure back in amd pretending it is OK because the resulting systems look and feel like Bitcoin.
abricq 4y ago
It seems a little optimistic, if not misleading, to say about Bitcoin "Bitcoin, Ethereum, and many disruptive applications [...] that have positive impact in numerous sectors, including [...] environment [...] to name a few". You can think of many advantages of Bitcoin (I surely think so), but please do not include "positive for the environment" as one of them, especially in the abstract of the paper.
HidyBush 4y ago
>Blockchain enables a digital society where people can contribute, collaborate, and transact without having to second-guess trust and transparency. in the blockchain the code is the law, so in order to trust the blockchain you have to trust its code. have you audited the bitcoin code? why do you trust it over anything else then? just admit that you trust the global community more than you trust international regulatory bodies. >It is the technology behind the success of Bitcoin, Ethereum, and many disruptive applications and platforms that have positive impact in numerous sectors, including finance, education, health care, environment, transportation, and philanthropy, to name a few. have they "disrupted" anything? is this a comprehensive explanation or plain propaganda? who would someone use such an elevator-speech terminology for a supposedly serious explanation?
- FabHK 4y ago
  > where people can contribute, collaborate, and transact without having to second-guess trust and transparency. Donate to the Ukraine and to the children and to the world peace here: 1BvTh1slsN0tAScam100%SrslyK Can't go wrong, it's on the blockchain and you don't have to second-guess trust!!11!!!11! /s
FabHK 4y ago
> The choice of cryptography to use determines the performance and guarantees of the blockchain. For example, Dogecoin blockchain clones Bitcoin but using simpler cryptographic functions to increase transaction throughput; the mining in Dogecoin is based on SCRYPT which is faster and easier to run than SHA256 used in Bitcoin. This, however, results in weaker security, less robust to attacks by dishonest nodes. 1. Isn't scrypt a key-derivation-function, and thus (by design) much slower and more work intensive than SHA-256 (a cryptographic hash)?? 2. Isn't anyway difficulty adjusted depending on the available hash power (such that a target block rate is reached), so that "faster and easier to run than SHA256" does not make any sense at all? Have the authors even understood PoW?
- rcxdude 4y ago
  Yes, this is complete nonsense. Block time and difficulty can both be adjusted independently of your work function (in fact it's a critical property of the work function that such adjustment is possible). The difficulty is automatically adjusted to keep to the target average block time of the network as the amount of mining increases and decreses. Dogecoin simply has a lower target block time than bitcoin (which, given equal mining power, would mean less difficulty), but also has a much lower difficulty because there's much less mining power on the network due to the relatively lower mining rewards (a function of how much currency the network awards miners at the moment and the price of the coin). Less mining power does roughly correlate to an easier attack on the network, but this is mostly independent of the technical decisions made by a given blockchain (there is some impact if e.g. the work function is sufficiently different that hardware from a larger network cannot be repurposed to mount an attack on a smaller network, e.g. using scrypt means bitcoin ASICs cannot mine on the network, making an attack much less easy to carry out. Ethereum's work function is designed to be memory bandwidth instead of compute limited, making GPUs generally optimal, and monero uses a funky algorithm designed to run best on general purpose CPUs). I will also note (and this is a point I don't see made often), that there is not really a specific mechanism in most blockchains to set the total mining rewards (and thus the total amount of effort mining which is incentivised) to an optimal value. It might be entirely excessive, in which case the network is secure but even more inefficient, or it might be insufficient, there is nothing which really sets this to a particular value. This is in part because it's hard to know exactly what level of mining is necessary (what's the difficulty required to fend off all attackers? probably depends on what they could gain from an attack, which is hard to assess), and because it depends on the price of the coin, which is something the network does not really have a means to assess within itself. (This is one of the reasons why I think bitcoin as a "long term store of value" does not make sense. The deflationary design requires ever-diminishing mining rewards, but the network will still require significant mining effort to secure it, especially if the amount of value stored keeps going up. In the 'bitcoin as currency' model, the transaction fees would keep the incentive present, but with a relatively low rate of transactions you will need extremely high transaction fees to secure the network, making it potentially quite an expensive store of value to maintain.
foxes 4y ago
>many disruptive applications and platforms that have positive impact in numerous sectors, including finance, education, health care, environment, transportation Hahaha, not at all. As for trust, well remember that the blockchain proves absolutely nothing about the real world. It only can prove things that happened on the chain. This is called the oracle problem.
RyEgswuCsn 4y ago
Isn't blockchains just git graphs where only the lucky ones get to push commits to?
cshg 4y ago
No matter the many critical comments this is actually a pretty concise summary of the technology / concepts behind blockchain including recent developments such as scalability / rollups and interoperability, which are hard to find good explanations for. Recommended read for anyone interested in the space from my perspective! Despite potential imperfections.
- soco 4y ago
  It could also do without the marketingspeak - it has way to go until it will become "disruptive".
throw0101a 4y ago
I try to also raise awareness of NIST's Blockchain Technology Overview, which is a good explainer: * https://csrc.nist.gov/publications/detail/nistir/8202/final https://csrc.nist.gov/publications/detail/nistir/8202/final See especially Figure 6 ("p. 42", 53 of the PDF), which is a flow chart to help you decide on whether blockchain may match one's use case. Extracted: * https://imgur.com/a/RlUj9Ed https://imgur.com/a/RlUj9Ed Generally you need the conditions of needing both (a) append-only log and (b) distributed/decentralized before considering blockchain 'technology'.

43 points by blopeur 4y ago

dandanua 4y ago

It is the technology behind the success of ... Here, I saved you a click.

tomschwiha 4y ago
Do you usually first click on the article or directly jump into the comments? I tend to do both at the same time.
- dandanua 4y ago
  Cryptosphere is a cesspool full of lies and manipulation. People who understand this will read the comments first, I guess.
- rvz 4y ago
  I assume that for each post on this site, everyone has read the article (and in this case, this paper) before jumping into the comments section to discuss what they have just read. It seems the person you have just replied to has already admitted that they have read as far as just one sentence before rushing here in minutes later. Perhaps they do this with every article they see. There are those who are unable to read beyond the headlines or the first paragraph and react here immediately. No wonder they are manipulated all the time these days as evident in their own reply below. Is that what it has gotten to on this site?
- djvdq 4y ago
  I usually start with comments. Only after that, if majority of the comments are not "this article is false and bad" I open the article. Is it good or bad? No idea.

jpgvm 4y ago

Blockchain as it stands still remains primarily an interesting solution looking for a killer problem. I think what it really needs is to find a problem that it's objectively better than the non-blockchain alternative. As a store of value, currency or payment network it's yet to be able to prove that. For more interesting applications, smart contracts etc the networks themselves are still struggling to find ways to keep transactions/operating costs in line with value. Even those more complex cases aren't yet objectively superior to other technology choices. I think we will find use-cases for byzantine-proof distributed ledger but nothing has yet been compelling enough to supplant other options.

medo-bear 4y ago
this is a very original and novel insight. thank you
arcticbull 4y ago
It's a lot like quantum computing. It's hip, and exciting, and easy to raise money for. But the set of algorithms that are better implemented by extant quantum computers than classical systems is, last I checked, the empty set.
k__ 4y ago
The killer problem is fake news. I don't think blockchains are the only or even best solutions to fake news, but the ecosystem build around them uses public-key cryptography for everything. A world where every piece of information is signed, could be a harsh blow for fake news. It's what PGP always wanted to go mainstream. Maybe, the money behind it (reasonable or not) is finally enough to motivate the mainstream.
- vesinisa 4y ago
  Ugh? Yes, fake news is about a trust problem - people trusting sources which spread nefariously incorrect or distorted views. But no, public key cryptography or blockchain does not solve this problem. I am not sure what do you even propose exactly but think for a moment what differentiates a "real news" and "fake news" source from each other, and you are back to square one. People who read fake news already now choose to trust and subscribe to their reporting.
- NikolaNovak 4y ago
  I'd love to hear more. A) fake news is hard to define and agree upon B) different people will have different criteria definition and Venn diagrams of fake news C1) many people and organizations start and distribute fake news knowing them to be such C2) many people and organizations start or propagate fake news while earnestly believing them Can you help understand how block chain or public key cryptography will help or address anything relating to fake news? Is there an underlying assumption that ascertaining identity will help? Because from my perspective majority of fake news are created and propagated by readily and eagerly identifiable people, whether potus or my cousin on Facebook and anything in between. In other words, today already I pretty much know who is relating any given piece of news. I may even know where or who originated them. It does not in the least solve the problem that my liberal and conservative, atheist and religious. Rich and poor, immigrant and local, technical and humanities etc neighbours have completely different parameters and selection of trust. Identifying the source helps not a bit with radically different selections of source. And then we get to "disagreeable" topics - how will block chain help those who fundamentally disagree on climate abortion religion economy foreign politics military basic income refugees healthcare rights etc. They will continue to pick and choose whatever our inherent bias is. There is this utopian notion that tech framework will solve a human problem.

_fizz_buzz_ 4y ago

> transact without having to second-guess trust and transparency Lots of people get scammed with crypto. Whatever web3 is solving, this ain’t it.

FabHK 4y ago

The article proclaims "the intermediaries" as the solution to the trust problem. That is incomplete in two ways: 1. Intermediaries are not the only solution to the trust problem, there are many many others. (See for example Bruce Schneider's Liars and Outliers, where he lists morality, reputation, institutions, security systems [1,2].) 2. Intermediaries don't only solve the problem of trust, but can also make things more efficient. If any two nodes need a connection, a graph needs O(N^2) edges. With a central intermediary, it only needs O(N) edges. [1,2] See https://www.schneier.com/books/liars-and-outliers https://www.schneier.com/books/liars-and-outliers, or https://www.wired.com/story/theres-no-good-reason-to-trust-blockchain-technology/ https://www.wired.com/story/theres-no-good-reason-to-trust-b...

wslh 4y ago

50 pages!

deleted 4y ago

[deleted]

mjburgess 4y ago

If you're trying to assess whether this is more propaganda, let me help: > Trust is the biggest bottleneck in realizing transactions. It is the biggest bottleneck in advancing the society. As a trust-less system, blockchain removes that bottleneck. Indeed, apparently trust in transactional system is our biggest problem. And indeed, apparently, blockchains provide that trust. here's me thinking its trust in social institutions which is our biggest problem, an issue made much worse by blockchain, which offers no systems of redress (perhaps the most significant benefit of institutions and trust).

arcticbull 4y ago
Trust in transactions isn't an issue at all. When was the last time you threw down your Visa card and worried about ... anything? They offer redress via chargebacks. You trust Visa, Visa trusts the merchants. Something goes wrong, call your bank. Ezpz. Now you may argue that you can't pay for your, uh, illegal or immoral material with a Visa card. That's a different matter. In my opinion, the government should recognize modern payments rails as critical infrastructure and require them to process all legal transactions without discrimination. A sort of payments net neutrality. [edit] You may also argue that merchant fees are "too high" - yeah they're high in America. They're 0.3% in Europe, because again, that's a job for regulation. They don't get card transaction rewards (because that's where the overwhelming majority of interchange goes) but that's the trade-off they've chosen to make. Replacing modern payment rails with magic beans that live in your computer solves literally nothing for the overwhelming majority of people, which indeed, is why the overwhelming majority of people never transact on-chain. They speculate on the sidelines from centralized, trusted exchanges. It's gambling on unregistered securities to most people.
- trevelyan 4y ago
  If you read the whitepaper it flags (first paragraph) that the problem with payment systems that rely on trusted third parties like Visa is not that they don't work but that these parties are compelled to mediate. You may not mind yourself -- Visa is useful -- but adding this kind of closure isn't cost-free (look at Wikileaks) and the fundamental innovation in how to do this without introducing any trusted third parties is a big deal. With that said, I agree most of the new POS variants and DAGs are sneaking closure back in amd pretending it is OK because the resulting systems look and feel like Bitcoin.

abricq 4y ago

It seems a little optimistic, if not misleading, to say about Bitcoin "Bitcoin, Ethereum, and many disruptive applications [...] that have positive impact in numerous sectors, including [...] environment [...] to name a few". You can think of many advantages of Bitcoin (I surely think so), but please do not include "positive for the environment" as one of them, especially in the abstract of the paper.

HidyBush 4y ago

>Blockchain enables a digital society where people can contribute, collaborate, and transact without having to second-guess trust and transparency. in the blockchain the code is the law, so in order to trust the blockchain you have to trust its code. have you audited the bitcoin code? why do you trust it over anything else then? just admit that you trust the global community more than you trust international regulatory bodies. >It is the technology behind the success of Bitcoin, Ethereum, and many disruptive applications and platforms that have positive impact in numerous sectors, including finance, education, health care, environment, transportation, and philanthropy, to name a few. have they "disrupted" anything? is this a comprehensive explanation or plain propaganda? who would someone use such an elevator-speech terminology for a supposedly serious explanation?

FabHK 4y ago
> where people can contribute, collaborate, and transact without having to second-guess trust and transparency. Donate to the Ukraine and to the children and to the world peace here: 1BvTh1slsN0tAScam100%SrslyK Can't go wrong, it's on the blockchain and you don't have to second-guess trust!!11!!!11! /s

FabHK 4y ago

> The choice of cryptography to use determines the performance and guarantees of the blockchain. For example, Dogecoin blockchain clones Bitcoin but using simpler cryptographic functions to increase transaction throughput; the mining in Dogecoin is based on SCRYPT which is faster and easier to run than SHA256 used in Bitcoin. This, however, results in weaker security, less robust to attacks by dishonest nodes. 1. Isn't scrypt a key-derivation-function, and thus (by design) much slower and more work intensive than SHA-256 (a cryptographic hash)?? 2. Isn't anyway difficulty adjusted depending on the available hash power (such that a target block rate is reached), so that "faster and easier to run than SHA256" does not make any sense at all? Have the authors even understood PoW?

rcxdude 4y ago
Yes, this is complete nonsense. Block time and difficulty can both be adjusted independently of your work function (in fact it's a critical property of the work function that such adjustment is possible). The difficulty is automatically adjusted to keep to the target average block time of the network as the amount of mining increases and decreses. Dogecoin simply has a lower target block time than bitcoin (which, given equal mining power, would mean less difficulty), but also has a much lower difficulty because there's much less mining power on the network due to the relatively lower mining rewards (a function of how much currency the network awards miners at the moment and the price of the coin). Less mining power does roughly correlate to an easier attack on the network, but this is mostly independent of the technical decisions made by a given blockchain (there is some impact if e.g. the work function is sufficiently different that hardware from a larger network cannot be repurposed to mount an attack on a smaller network, e.g. using scrypt means bitcoin ASICs cannot mine on the network, making an attack much less easy to carry out. Ethereum's work function is designed to be memory bandwidth instead of compute limited, making GPUs generally optimal, and monero uses a funky algorithm designed to run best on general purpose CPUs). I will also note (and this is a point I don't see made often), that there is not really a specific mechanism in most blockchains to set the total mining rewards (and thus the total amount of effort mining which is incentivised) to an optimal value. It might be entirely excessive, in which case the network is secure but even more inefficient, or it might be insufficient, there is nothing which really sets this to a particular value. This is in part because it's hard to know exactly what level of mining is necessary (what's the difficulty required to fend off all attackers? probably depends on what they could gain from an attack, which is hard to assess), and because it depends on the price of the coin, which is something the network does not really have a means to assess within itself. (This is one of the reasons why I think bitcoin as a "long term store of value" does not make sense. The deflationary design requires ever-diminishing mining rewards, but the network will still require significant mining effort to secure it, especially if the amount of value stored keeps going up. In the 'bitcoin as currency' model, the transaction fees would keep the incentive present, but with a relatively low rate of transactions you will need extremely high transaction fees to secure the network, making it potentially quite an expensive store of value to maintain.

foxes 4y ago

>many disruptive applications and platforms that have positive impact in numerous sectors, including finance, education, health care, environment, transportation Hahaha, not at all. As for trust, well remember that the blockchain proves absolutely nothing about the real world. It only can prove things that happened on the chain. This is called the oracle problem.

RyEgswuCsn 4y ago

Isn't blockchains just git graphs where only the lucky ones get to push commits to?

cshg 4y ago

No matter the many critical comments this is actually a pretty concise summary of the technology / concepts behind blockchain including recent developments such as scalability / rollups and interoperability, which are hard to find good explanations for. Recommended read for anyone interested in the space from my perspective! Despite potential imperfections.

soco 4y ago
It could also do without the marketingspeak - it has way to go until it will become "disruptive".

throw0101a 4y ago

I try to also raise awareness of NIST's Blockchain Technology Overview, which is a good explainer: * https://csrc.nist.gov/publications/detail/nistir/8202/final https://csrc.nist.gov/publications/detail/nistir/8202/final See especially Figure 6 ("p. 42", 53 of the PDF), which is a flow chart to help you decide on whether blockchain may match one's use case. Extracted: * https://imgur.com/a/RlUj9Ed https://imgur.com/a/RlUj9Ed Generally you need the conditions of needing both (a) append-only log and (b) distributed/decentralized before considering blockchain 'technology'.