Blockchain in a Nutshell

If you&#x27;re trying to assess whether this is more propaganda, let me help:<p>&gt; 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.<p>Indeed, apparently trust in transactional system is our biggest problem. And indeed, apparently, blockchains provide that trust.<p>here&#x27;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).

Blockchain as it stands still remains primarily an interesting solution looking for a killer problem.<p>I think what it really needs is to find a problem that it&#x27;s objectively better than the non-blockchain alternative.<p>As a store of value, currency or payment network it&#x27;s yet to be able to prove that.<p>For more interesting applications, smart contracts etc the networks themselves are still struggling to find ways to keep transactions&#x2F;operating costs in line with value. Even those more complex cases aren&#x27;t yet objectively superior to other technology choices.<p>I think we will find use-cases for byzantine-proof distributed ledger but nothing has yet been compelling enough to supplant other options.

&gt;Blockchain enables a digital society where people can contribute, collaborate, and transact without having to second-guess trust and transparency.<p>in the blockchain the code is the law, so in order to trust the blockchain you have to trust its code. have <i>you</i> 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.<p>&gt;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.<p>have they &quot;disrupted&quot; anything? is this a comprehensive explanation or plain propaganda? who would someone use such an elevator-speech terminology for a supposedly serious explanation?

The article proclaims &quot;the intermediaries&quot; as the solution to the trust problem.<p>That is incomplete in two ways:<p>1. Intermediaries are not the only solution to the trust problem, there are many many others. (See for example Bruce Schneider&#x27;s <i>Liars and Outliers,</i> where he lists morality, reputation, institutions, security systems [1,2].)<p>2. Intermediaries don&#x27;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.<p>[1,2] See <a href="https:&#x2F;&#x2F;www.schneier.com&#x2F;books&#x2F;liars-and-outliers" rel="nofollow">https:&#x2F;&#x2F;www.schneier.com&#x2F;books&#x2F;liars-and-outliers</a>, or <a href="https:&#x2F;&#x2F;www.wired.com&#x2F;story&#x2F;theres-no-good-reason-to-trust-blockchain-technology&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.wired.com&#x2F;story&#x2F;theres-no-good-reason-to-trust-b...</a>

&gt;many disruptive applications and platforms that have positive impact in numerous sectors, including finance, education, health care, environment, transportation<p>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.

&gt; 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.<p>1. Isn&#x27;t scrypt a key-derivation-function, and thus (by design) much slower and more work intensive than SHA-256 (a cryptographic hash)??<p>2. Isn&#x27;t anyway difficulty adjusted depending on the available hash power (such that a target block rate is reached), so that &quot;faster and easier to run than SHA256&quot; does not make any sense at all?<p>Have the authors even understood PoW?

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

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

I try to also raise awareness of NIST&#x27;s <i>Blockchain Technology Overview</i>, which is a good explainer:<p>* <a href="https:&#x2F;&#x2F;csrc.nist.gov&#x2F;publications&#x2F;detail&#x2F;nistir&#x2F;8202&#x2F;final" rel="nofollow">https:&#x2F;&#x2F;csrc.nist.gov&#x2F;publications&#x2F;detail&#x2F;nistir&#x2F;8202&#x2F;final</a><p>See especially Figure 6 (&quot;p. 42&quot;, 53 of the PDF), which is a flow chart to help you decide on whether blockchain may match one&#x27;s use case. Extracted:<p>* <a href="https:&#x2F;&#x2F;imgur.com&#x2F;a&#x2F;RlUj9Ed" rel="nofollow">https:&#x2F;&#x2F;imgur.com&#x2F;a&#x2F;RlUj9Ed</a><p>Generally you need the conditions of needing both (a) append-only log <i>and</i> (b) distributed&#x2F;decentralized before considering blockchain &#x27;technology&#x27;.

No matter the many critical comments this is actually a pretty concise summary of the technology &#x2F; concepts behind blockchain including recent developments such as scalability &#x2F; rollups and interoperability, which are hard to find good explanations for.<p>Recommended read for anyone interested in the space from my perspective! Despite potential imperfections.

Isn&#x27;t blockchains just git graphs where only the lucky ones get to push commits to?

<i>It is the technology behind the success of ...</i><p>Here, I saved you a click.

50 pages!