What Block Chain Projects Learn from Open Source?

I’ve been involved with open source over a decade now. I’ve been part of small projects with innovative ideas which grew into large projects with solid communities. I’ve also witnessed how dysfunctional communities can suck the energy of projects for years. All that thanks to the open source development and collaboration.

I’ve been involved with open source over a decade now. I’ve been part of small projects with innovative ideas which grew into large projects with solid communities. I’ve also witnessed how dysfunctional communities can suck the energy of projects for years. All that thanks to the open source development and collaboration.

In recent times, I’m active on the blockchain space as well: reading, writing, and contributing to projects. And I came to the conclusion that blockchain projects are startups with open development and open business models. And to be successful, the first and foremost, blockchain startups have to learn how to build communities the open source way.


Open source code

One of the fundamental premises of blockchain is decentralization and giving control and data back to the user. Such decentralization cannot be achieved without transparency and openness. If the source code is closed, that is no different to the centralized closed systems of today. Without making the code open, there is no way to read and confirm that a system is doing what it is promising to do.

There are projects that are trying to avoid it, but even they recognize that the code has to be open to a certain level at a minimum. For example, Hedera Hashgraph (which is technically not a blockchain project, but a similar class of software) has said the code cannot be freely distributed (forked), but it will be open for review.

That proves our premise: blockchain projects, first and foremost are open source projects. Whether this can be classified as open source according to “The Open Source Initiative” is not in the scope of this article. The point is, if the source code is not readable/verifiable, there is no point in having something run on a non-trusted blockchain platform.


Open runtime

In addition to the source being open, what differentiates blockchain from non-blockchain open source projects is that fact that for the first the runtime is open as well. An open source project can be developed in the open, but then run and consumed as an open core, as a service, or as part of a closed system. Public blockchain (not looking into private ones here) are permissionless, anyone can join and leave a network, anyone can run a node or two. It represents a trustless and borderless runtime with open governance.


Open data

Another distinct aspect of blockchain is that blockchain projects in addition to the open source code, open runtime, also have open data. Anyone can fork the code (the client application), fork the data (the blockchain history) and start a new network. That ultimately makes blockchain projects the most open software systems ever existed. Open code, open data, open runtime, open business model, ensure openness in multiple dimensions.


Open business model

Blockchain startups are a very unique mix of open source development, and open value capture models, all blended into one at source code level. While a non-blockchain based open source project is typically used for creating value through collaborative development and open adoption, capturing value happens through a separate business model. The business model can be thought in advance or defined later such as SaaS, open core, subscription, etc.

With the blockchain projects, the business model is described in a white paper, and the token model capturing value is implemented in the source code in advance. All that makes blockchain projects a unique blend of value creation and instant capture and distribution.


Why be so open?

Most of the blockchain projects are aiming to become some kind of platform or a hub with open standards and protocols that will attract and be adopted by the developers and consumed by users subsequently. The primary way these platforms and protocols attract developers is not through technical superiority over non-blockchain technology, but by the unique decentralization, characteristics achieved through openness in multiple dimensions.

These platforms have to be open in order to become more attractive than the existing closed systems which already have all the developers and users on them.

Being open is not only a prerequisite for its transparency, but also for its distribution and adoption. That is especially valid for projects which are aimed to be consumed as a platform or protocol by developers rather than end users. Open source is the primary way for developers to explore, learn and start using a project.


Isn’t “open” a weakness?

There was a time when being open source was considered a dangerous act as a competitor could copy and steal the code or the ideas. The recent times proved that being open source is the primary way for developer adoption, especially for developer-centric platforms, tools, and libraries. But as we have seen above, blockchain is also open runtime and open data as well. Which means anybody can fork the code and the data and start a parallel network.

That makes a project vulnerable to even more kinds of splits/forks and value grab. And we have seen this happened many times with the forks of the most popular blockchain networks such as Bitcoin and Ethereum. Yet, these projects are performing better than projects which are looking for ways to prevent forking but also lack the ability to attract followers. That is because being open is actually a sign of strength. If a network is so open and has survived forks and attacks, it makes its community only stronger.

We can observe the act of being open not only in projects, but also people and organizations. Today, people and organization rush into sharing and showing off their knowledge through open source code, conference talks, blogging, tweeting, etc.

The innovation is happening so fast in certain areas that by the time somebody can understand and copy an idea, the inventor of the idea will have created the next one. And being a copycat in a winner takes all markets has a negative networking effect on community growth. In the journey to conquer the closed and centralized systems, being open is the primary weapon.


Hype is different than a community

I’ve seen many times, how successful Initial Coin Offering (ICO) investors measure hype around a project for an early investment. Typically such a measure works only when the early investment is accompanied by an early exit. In practical terms that means identifying the most hyped ICO, and selling all tokens as soon as it hits an exchange.

Measuring such a hype is done by simple statistics around Twitter followers, Facebook followers, Reddit subscribers, Telegram users, etc. These metrics have a little value for measuring a community strength for the following reasons:

  • Metrics are artificially inflated with fake accounts, paid followers, subscribers, etc;
  • The ICOs themselves run airdrops campaigns and distribute tokens for following, subscribing, joining, etc;
  • These are the wrong metrics for measuring a developer-centric community;

What I mean by the latter is that an open source project that is going to be used by developers (as a platform, protocol, whatever) should measure developer activity, rather than airdrop hunter activities. None of the actions mentioned above are building stickiness in a project community. In fact, all of these activities are purposefully skewing the community metrics using temporary incentives.


Community over market cap

The Apache Software Foundation (ASF) is one of the biggest and oldest software foundations, home of hundreds of popular open source projects. And there, we (I’m a member, committer, and PMC there) have a very fundamental belief that says: Community over Code. As a software foundation, we are all about code, and wouldn’t have a reason for existing without the code, but this slogan actually codifies how we do things, and how we go about decision making.

ASF is first a home for communities rather than a repository for code. The code is the by-product of a good and healthy community. And we first try to grow healthy communities united around projects.

If we look for example how an ASF project measures its quarterly activity and progress, that is by the number of mailing list subscribers, emails sent, issues opened/closed, pull requests created/merged, software releases done, committers and PMCs voted for. The last one is a very important long term indicator for the health of a project measuring the ultimate level of commitment of community members to the success of the projects.

If you look at these metrics, these are all about activities performed by technical people rather than temporarily incentivised airdrop hunters. These activities are harder to fake as they require doing something for the project (usually consuming brain power and time) rather than clicking a like/follow button which easier to outsource.

A blockchain project has a more complex ecosystem than an open source project alone. There are developers, but also miners (or their equivalent for running the network), investors, and eventually users. Measuring only the developer activity won’t be indicative enough for the full ecosystem, but focusing on the right metrics would be a good start.

In a similar spirit to the ASF’s “Community over Code”, I think the cryptocurrencies would benefit from “Community over Market Cap”. A healthy community is a far more important long-term measure than a temporary large market cap. The price of a token/coin and its market cap can be artificially manipulated or temporarily affected by a bear market. A strong and healthy community can hodl and survive ups and downs. An unhealthy community, without any stickiness to the project would fall apart anyway.


Building communities the blockchain way

Are there good examples of building stickiness and community around the new blockchain projects? I have seen a few projects that have recognized the importance of the community from the very beginning and approached their token sale completely uniquely. These projects aimed to familiarizing the prospective early investors with the project goals, white paper, mission and not only ask for money. There are definitely more examples, but the projects with unique token sale processes I have seen are the following.

  • DFINITY project had a registration process that cost close to 10$. Then they gave that money back in the form of a swag and a free t-shirt. But it was a good method to get rid of the people who are there only for the noise and not even willing to commit 10 bucks.
  • QuarkChain ICO process had quiz with 25 not very simple questions. In order to join the token sale, one had to be part of their telegram channel from early days + have a good score on the quiz + pass the lottery. While the lottery and telegram channel components were already present in other ICOs at the time, the quiz actually forced candidates to find the answers in a short time, and learn about the project (that led to a blackmarket of quiz answers, but it was a nice attempt the least).
  • One of the best executions of community building during ICO phase has been of Mainframe. Mainframe run three crowdgift campaigns:
  • Proof of Being – where tokens where literally physically dropped from the air in certain locations around the world. To get tokens, one had to get to the meetup, meet the team and grab some tokens.
  • Proof of Freedom – where participants had to answer the question why Mainframe mission mattered to them, and submit the answers in any form: tweet, blog post, audio, video, drawing, etc. I also took part in it by writing a blog post.
  • Proof of Heart – where participants were asked to donate Ether which then went to a few non-profit organizations.

We can see how Mainframe used three different methods (each with its pros and cons) to build stickiness, awareness and community around its project and even managed to raise money for non-profit organizations.

Blockchain projects are especially sensitive to Metcalfe’s law and their value is directly proportional to the size of its community. A token not used by anybody is worth nothing. A platform without developers is a zombi platform. Building a community around the crypto project is as important as building the platform itself, if not more. While the crypto world knows how to raise money, the open source world knows how to build communities. They can learn something from each other.


Top 10 Best Blockchain Programming Language for Blockchain Programmer

Top 10 Best Blockchain Programming Language for Blockchain Programmer

We aim at equipping you with every necessary knowledge of the best programming languages for blockchain and you'll learn more 10 Best Blockchain Programming Language for Programmer: C++, Java, Python, Ruby, Solidity, Go, JavaScript...

We aim at equipping you with every necessary knowledge of the best programming languages for blockchain and you'll learn more 10 Best Blockchain Programming Language for Programmer: C++, Java, Python, Ruby, Solidity, Go, JavaScript...

If you’re a tech-oriented person like me, chances are you’ve wondered at least once about all those latest fusses regarding blockchain and cryptocurrencies. So, what is this blockchain and why’d you be tempted to learn more about it? Blockchain, as the name suggests, is a chain of blocks; connected sequentially using complex cryptographic logic.

This technology was implemented first by Satoshi Nakamoto and was first used in the implementation of the popular BitCoin cryptocurrency. The blockchain technology is being used heavily in the industry, thanks to the high-level of security it provides in business transactions. From corporate firms to industrial banks, blockchain developers are sought everywhere equally. So, wielding this modern-day skill by learning the best blockchain programming language guarantee you an edge over your fellow developers.

Which are the best programming languages for blockchain? Developers are presently utilizing prevalent programming languages like C++ and Java to manufacture custom blockchain programs. What’s more, digital money specialists have made languages like Simplicity and Solidity that are explicitly intended for blockchain improvement.

The worldwide Blockchain market is right now worth an expected $1.2 billion and specialists foresee that it will arrive at a $57 billion valuation by 2025, developing at over 69% every year.

Significant enterprises and investors are teaming up with Blockchain counseling organizations to grow new digital currency innovation, savvy contracts, conveyed records for customary banks, gaming tokens, and inventory network the executives frameworks.

What Is Blockchain?

Customary financial uses a bank as the record and mediator. To move cash to a companion, an individual should initially contact their own bank and request that they move cash to a particular record number. The bank checks the sender’s record for assets, moves those assets to the goal, and records the exchange on the sender’s record. The accepting bank must accomplish something very similar.

In any case, the issue with this customary financial framework is that records are put away inside and are defenseless against hacking and control.

Blockchain disposes of this hazard by putting away all records online in a decentralized, unknown record that can be gotten to by anybody. Blockchain uses squares, or accumulations of information, like spreadsheet lines and segments, to store information. Squares are added to the “chain” in successive request.

In contrast to conventional bank records, which are put away inside, each blockchain client has a total record of the whole blockchain on their PC. This implies they can rapidly discover any exchange that has ever happened in the event that they have the comparing hash code. Since that information is put away freely, it can never be changed or erased — giving clients genuine feelings of serenity and trust in the framework.

Organizations keen on exploiting the blockchain upset should scan for up-and-comers with skill in the accompanying programming languages.

Here are the best programming languages for Blockchain

1. C++

C++ keeps on being one of the most famous programming languages in the tech world and is a prevailing power in the blockchain business also. The article arranged language is ideal for blockchain improvement, since it utilizes similar standards, for example, epitome, deliberation, polymorphism, and information covering up, as blockchain to avoid incidental alters to information.

Engineers additionally prize C++ in view of its memory control abilities. The language helps keep squares secure and deal with an enormous number of asset demands by enabling each system hub to acknowledge or dismiss individual squares.

C++ is additionally utilized broadly by blockchain advancement administrations due to the manner in which it handles parallel undertakings and stringing. The language is equipped for taking care of both parallel and non-parallel assignments, notwithstanding improving single-string execution.

EOS is an awesome case of a blockchain program worked with C++. The open source programming was discharged by Square in 2018 and is intended to process exchanges more rapidly than choices by restricting the product to only 21 square creating hubs. This enables the product to affirm an exchange in under a second and settle it in only two minutes.

2. JavaScript

GitHub as of late positioned JavaScript as the most mainstream language for developers — with a fantastic 95% of sites utilizing it here and there. Be that as it may, JavaScript isn’t just the lord of web advancement; the adaptable programming language is additionally utilized broadly for blockchain improvement.

One reason why blockchain designers prize JavaScript is a direct result of the manner in which it handles offbeat code. This is significant in blockchain, as thousands or even a great many exchanges might be started simultaneously. Offbeat, parallel programming empowers a program to finish numerous activities all the while. Standard, synchronous programming just can’t deal with that volume.

By running numerous activities on the double, offbeat code can improve programming responsiveness and application execution. This empowers blockchain projects to deal with the enormous volume of activities without hindering execution and disappointing clients.

You may also like: How to Build a Blockchain in JavaScript.

3. Java

The only language that can challenge the reign of C++ in the industry is Java, and for good reasons so. Java is in many ways similar to C++ regarding its object-oriented approach and a vast community of third-party applications and platforms. The main reason to use Java as the de-facto blockchain programming language in the industry is, however, its highly-capable portability.

Programs written in Java are portable across any computational device, as they don’t rely on system-specific architecture, instead uses the universal JVM(Java Virtual Machine) for execution. This makes Java one of the best programming languages for blockchain.

4. Python

Python is probably THE most trending programming language you can learn these days!

It's very popular because it's easy to learn and use, runs on all operating systems and allows you to build a broad variety of programs: Be that web applications, desktop applications, utility scripts or using it for data science and machine learning.

You'll do so whilst building your own Blockchain and Cryptocurrency. These are of course also highly trending topics and not a lot of people understand what a Blockchain really is, you'll learn a lot about the core concepts of the Blockchain and you'll see how Python can be used for the many aspects that make up a Blockchain and Cryptocurrency.

You may also like: Building a Blockchain with Python.

5. Solidity

Solidity is a savvy contract and blockchain improvement language that is utilized broadly by Ethereum designers. The area explicit language utilizes a significant number of indistinguishable standards and punctuation from JavaScript to make high-caliber, decentralized applications.

Engineers lean toward the language since it enables them to compose elevated level code for the Ethereum blockchain arrange, the second-most famous blockchain digital currency, which can be assembled into low-level machine code. It additionally enables people to use the Ethereum advanced exchange record to make brilliant agreements between organizations.

The agreement situated language utilizes invariants, preconditions, and post-conditions to streamline the advancement procedure and to make the agreement age process easier for clients.

Solidity is at present accessible on a scope of blockchain stages, including Ethereum, Ethereum Great, Tendermint, and Counterparty. It’s utilized for a scope of utilizations, including business contracts, barters, crowdfunding, and that’s just the beginning.

6. Ruby

Although quite old and tested by the industry, Ruby gained momentum as a blockchain programming language in the last couple of years or so. Ruby, an interpreted high-level language with object-oriented features, much like Python, can be a viable blockchain coding language for uncountable reasons. It offers developers the ability to prototype their vision rapidly using open source third-party APIs and plugins.

The Ruby ecosystem is thriving with loyal contributors since its inception as the de-facto web language starting from the first half of this millennium. It’s especially prevalent within the Asian developers, the most substantial fraction of open source blockchain developers.

7. Simplicity

Simplicity is a fresh out of the plastic new programming language that was discharged in November 2017 and planned explicitly for shrewd agreements and blockchain improvement. The language conceals low-level consistent parts from architects so as to expand efficiency and stay away from engineer interruptions, which is one motivation behind why it is quickly winding up well known in the network.

Like C++, Effortlessness is an item arranged language that uses indistinguishable standards from blockchain to forestall blunders and changes to information. It additionally utilizes Merklized Theoretical Sentence structure Trees to sort out the projects into trees — along these lines taking into account littler exchange sizes and lessening square space prerequisites.

The language’s makers, Blockstream, are as yet extending the language and its abilities. Designers can hope to see Simplicity being utilized in more applications towards mid-2020 once the language is incorporated into Bitcoin and its highlights are concluded.

8. Go

The brainchild of Robert Griesemer, Rob Pike, and Ken Thompson, pioneer of modern programming languages, Go is the best blockchain programming language for building hyper ledger fabric. The statically-typed yet compiled language is on par the performance level needed by a blockchain coding language. Go comes with every advanced feature you’d need when building your first blockchain, namely classes and inheritance, generics, annotations, constructors, and exceptions.

Go offers top-notch concurrency support in blockchain applications, thanks to its smart implementation of channels and interfaces. So, it’s one of the best programming languages for blockchain when it comes to developing a system that is not only efficient but also lightning fast.

9. Rust

The newest blockchain programming language on the block currently, Rust aims at providing open source devs the capability to build fast and efficient blockchain systems. We found Rust to be exceptionally good when it comes to CPU-bound tasks. You can take either a functional approach or an imperative one with Rust for developing your blockchain.

It’s one of the best programming languages for blockchain due to its highly-capable mechanism of handling mutable states. The Rust compiler provides awe-inspiring optimization of your blockchain. The fast, memory safe, and exclusively concurrent nature of this blockchain coding language makes it most suitable for developing real-world blockchains.

10. PHP

Although dimmed not suitable for modern web anymore, PHP still covers the majority of web systems. It can be utilized to build simple to complex blockchain systems as well, thanks to its object-oriented features and a vast active open source community.

If you’re a new programmer looking for getting your hands dirty at blockchain coding, PHP might turn out to be the best option for you. A considerable number of PHP developers will guarantee a ready workforce in case you develop something highly capable and intend on going corporate.

Summary

Blockchain is here to stay. The popular record-keeping technology is what makes cryptocurrency exchanges possible and is widely used by corporations, individuals, and blockchain consulting services for software development.

Developers can easily use popular programming languages like C++ and Java for blockchain development. Alternatively, the community has recently created blockchain-specific languages like Solidity and Simplicity which make cryptocurrency development a smooth process.

Expect to see more original languages spring up over the next several years, as the blockchain market continues to grow rapidly and cryptocurrency begins to be used by ever-larger numbers of people.

Thank for reading!

What is in a block? - Blockchain

In my previous article, I tried to described the concept of a blockchain with code. This time, I'll try to describe the structure of a single block. I will use the Bitcoin blockchain to explain blocks, but keep in mind that the concepts will remain more or less the same. It could be useful to read my&nbsp;<a href="https://dev.to/damcosset/trying-to-understand-blockchain-by-making-one-ce4" target="_blank">last article</a>to understand a few things first.

Introduction

In my previous article, I tried to described the concept of a blockchain with code. This time, I'll try to describe the structure of a single block. I will use the Bitcoin blockchain to explain blocks, but keep in mind that the concepts will remain more or less the same. It could be useful to read my last articleto understand a few things first.

Structure of a block

A block is a container data structure. In the Bitcoin world, a block contains more than 500 transactions on average. The average size of a block seems to be 1MB (source). In Bitcoin Cash ( a hard fork from the Bitcoin blockchain ), the size of a block can go up to 8MB. This enables more transactions to be processed per second.

Anyway, a block is composed of a header and a long list of transactions. Let's start with the header.

Block Header

The header contains metadata about a block. There are three different sets of metadata:

  • The previous block hash. Remember that in a blockchain, every block is inherits from the previous block because we use the previous block's hash to create the new block's hash. For every block N, we feed it the hash of the block N-1.
  • Mining competition. For a block to be part of the blockchain, it needs to be given a valid hash. This contains the timestamp, the nonce and the difficulty. Mining is another crucial part of the blockchain technology, but it is outside the scope of this article.
  • The third part is a merkle tree root. This is a data structure to summarize the transactions in the block. And we will leave it at that for now. More on this later.
Block identifiers

To identify a block, you have a cryptographic hash, a digital signature if you will. This is created by hashing the block header twice with the SHA256 algorithm. For example, this is a block. I will refer to this block as an example for this article.

The block header hash for this particular block is (right column): 000000000000000000301fcfeb141088a93b77dc0d52571a1185b425256ae2fb

We also can see the previous block's hash (right column): 0000000000000000004b1ef0105dc1275b3adfd067aed63a43324929bed64fd7

Remember that we used the second hash to create the first. Every block uses the previous block's hash to construct its own hash. The block hash is a unique identifier. You won't find two blocks with the same hash.

The other way to identify a specific block is the block height. The is the position of the block in the blockchain. Our example's block is in the 500312 position. This means that there are 500311 blocks before this one. Since the creation of the Bitcoin blockchain in 2009, 500312 blocks have been created ( at the time of writing obviously ).

A block height is not unique. Several blocks can compete for the same position in the case of a fork, like Bitcoin Cash for example.

Merkle Trees

The transactions in a block are contained in a structure called a merkle tree or binary hash tree.

I feel that topics like that are easier to understand with actual examples. So we'll go coding for this. A merkle tree is constructed by recursively hashing pairs of nodes ( in this case, transactions ), until there is only one hash, called the root or merkle root. If we stay in the Bitcoin world, the cryptographic hash algorithm used is SHA256. This is applied twice each time.

An example: We have a block with 4 transactions. For the sake of simplicity, each transaction is a string:

const tA = 'Hello'
const tB = 'How are you?'
const tC = 'This is Thursday'
const tD = 'Happy new Year'

To construct our merkle tree, we start from the bottom. We take each transaction and double-hash them. I'll use the js-sha256 package here.

const sha256 = require('js-sha256').sha256

// Double-hashing here
const hA = sha256(sha256(tA))
const hB = sha256(sha256(tB))
const hC = sha256(sha256(tC))
const hD = sha256(sha256(tD))

//Results
52c87cd40ccfbd7873af4180fced6d38803d4c3684ed60f6513e8d16077e5b8e //hA
426436adcaca92d2f41d221e0dd48d1518b524c56e4e93fd324d10cb4ff8bfb9 //hB
6eeb307fb7fbc0b0fdb8bcfdcd2d455e4f6f347ff8007ed47475481a462e1aeb //hC
fd0df328a806a6517e2eafeaacea72964f689d29560185294b4e99ca16c63f8f //hD

Ok, great. Now remember that I wrote a merkle tree is constructed hashing pairs of nodes. So, we will pair our transactions and concatenate their hashes. Then, we will double hash them too. We will create a hash using the hashes hA and hB, and another for hC and hD. Then, we repeat that process until we have only one hash left and no more pairs to work with. The last hash will be our merkle root.

With only four transactions, this will be rather quick:

//Pairing hA and hB

const hAB = sha256(sha256(hA + hB))
//5dc23d1a2151665e2ac258340aa9a11ed227a4cc235e142a3e1738333575590b

//Pairing hC and hD

const hCD = sha256(sha256(hC + hD))
//ff220daefda29821435691a9aa07dd2c47ca1d2574b8b77344aa783142bae330

// We do it again. We pair hAB and hCD
// This is our root!
const hABCD = sha256(sha256(hAB + hCD))
//301faf21178234b04e1746ee43e126e7b2ecd2188e3fe6986356cc1dd7aa1377

The node at the top of the merkle tree is called the root. This is the information that is stored in the block header in each block on the blockchain. This is how transactions are summarized in each block. In our example block given earlier, the merkle root can be found in the right column: 

a89769d0487a29c73057e14d89afafa0c01e02782cba6c89b7018e5129d475cc

It doesn't matter how many transactions are contained in a block, they always will be summarized by a 32 bytes hash.

Note: The merkle tree is a binary tree. If there is an odd number of transactions, the last one will be duplicated so we can construct our tree.

Because all the leaves in our tree depends on other leaves, it is impossible to alter one leaf without altering others. If you change only one leaf ( one transaction ), the hash changes, therefore the hash you constructed by pairing it with another leaf changes, therefore the merkle root will be different.

You can prove that any transaction is included in a block by creating a authentification path or merkle path. You only need to know log base 2(N) 32-byte hashes. For example:

-For my 4 transactions merkle tree:

log base 2( 4 ) = 2 => If I have a path of 2 hashes for a tree of 4 transactions, I can manage to prove if a transaction belongs to this merkle tree.

For a 16 transactions merkle tree:

log base 2( 16 ) = 4 => If I have a path of 4 hashes for a tree of 16 transactions, I can manage to prove if a transaction belongs to this merkle tree.

log base 2( 1500 ) = 10.55 => If I have a path of 11 hashes for a tree of 1500 transactions, I can manage to prove if a transaction belongs to this merkle tree.

Perhaps a little diagram will help.

There are 16 leaves in this tree. We construct our tree from the bottom up by pairing each leaf. Now, anybody can prove that the leaf I ( in orange ) is part of this block by having the path given in green. We have only 4 hashes, but that is enough to know if the leaf I belongs here. That is because with those informations, we are able to construct every single leaf we need( in yellow ). We can create IJIJKLIJKLMNOP and the root and check if those hashes correspond. This is why it is very complicated to cheat a blockchain. To change one thing means you must change everything.

Well, that's pretty much what a block contains in the Bitcoin blockchain. Hope it helped!


Video explanation of blockchain

Two years ago, the hack to get an investment in your startup was to shout: “We are using the Blockchain!” The Blockchain&nbsp;<a href="https://medium.com/@pavelkravchenko/decline-of-blockchain-hype-and-rise-of-a-common-sense-8de5789a794d" target="_blank">was</a>&nbsp;the magic term that nobody understood, but had the label of “the next big thing”. That is why investors were investing like mad into companies that said they are using it. If only one of those startups hit the jackpot, the investors would become (more) insanely rich.

Two years ago, the hack to get an investment in your startup was to shout: “We are using the Blockchain!” The Blockchain was the magic term that nobody understood, but had the label of “the next big thing”. That is why investors were investing like mad into companies that said they are using it. If only one of those startups hit the jackpot, the investors would become (more) insanely rich.


Did it prosper? Is it Alive?

Now two years later, we see big companies like ING executing pilots with Blockchain as a way to store contracts. Accenture and the United Nations have created a solution that will register the refugees of the world inside of a Blockchain.


I know almost nothing about the Blockchain technology and want to get some feeling about what is going on. For almost three years after the introduction of the Blockchain as a new technology in the bleeding edge tech startups, the registration of people, housing and companies were promised to be open via the Blockchain. But it is still not here. What is this Blockchain and will it really be a revolution?

No reading, here are some videos

Since a picture is worth a thousand words, here are a few videos that explain the complex technology in a way everybody can understand. I have selected these videos in such a way that you can watch them one-by-one and have a clear understanding at the end. There is some overlap between the videos but that will help getting a better understanding.


Understand the Blockchain in Two Minutes (IFTF 2m25)

This video by Institute for the Future (IFTF) is ClearFast and gives a great insight on what the Blockchain technology is.


https://www.youtube.com/watch?v=r43LhSUUGTQ


The real value of bitcoin and crypto currency technology — The Blockchain explained (DutchChain 6m15)

A bit dull :) but clear and helps to refine the message of the previous video. It only takes 6 minutes to watch. This video is created by the Dutchchainorganization.


https://www.youtube.com/watch?v=YIVAluSL9SU


Blockchain Technology Explained: What is a Blockchain? (PassKit 4m)

Pretty clear story by PassKit …..


https://www.youtube.com/watch?v=eXJHPDs4M3Y


How Bitcoin Works in 5 Minutes (Technical) (CuriousInventor 5m25)

In this video the part of voting in the network takes is explained. Voting is the essential part of the Blockchain that determines the legitimacy of the transactions in the Blockchain.


https://www.youtube.com/watch?v=l9jOJk30eQs


Blockchain definition

The definition of “blockchain” on Wikipedia is “a distributed database that is used to maintain a continuously growing list of records called blocks… By design, blockchains are inherently resistant to modification of the data.”


In its core, the database behind blockchain is a ledger containing all transaction records. The ledger is distributed, which means there isn’t a single central point where the records are saved. It provides a transparent way where transactions between two parties are verifiable and are stored permanently. Any transaction of ownership can be stored into the blockchain.

In case you have more time to read, you can check out this article on ITNEXT where the most frequently asked questions about Blockchain are answered by Ivo van der Nagel.

Another great read is this Blockchain for Dummies book, made by IBM. You can read it if you need more background information and better understanding after watching the videos and reading the article mentioned above.


Blockchain Summarized

In various videos and articles the Blockchain is summarized with the use of one of the following three set of characteristics (at least).

No consensus on key characteristics

I find this very interesting: In 2009, the Blockchain was implemented for the first time. This technology is still quite new that even on the key characteristics there is no consensus. The big question that pops up is: is this a big hype or just something so complex that not everybody understands it? And if this is only a big hype, why venture capitalists are investing millions in it. And why the United Nations is betting the lives of refugees on it?

Everybody seems to dream about a more peer-to-peer network for registration of valuables. It doesn’t really matter to people what the valuables are, it can be money, houses, documents, or identities. People dream about what would happen when they are not dependent on a governmental or financial organisation. Removing the red tape to increase the speed, reduce the cost of transactions, and create an opening for machine-to-machine transactions are the main ingredients in many Science Fiction stories.

And these dreamers ignore the complex center of the Blockchain technology. They ignore or do not know that it works only given specific rules or balance of rules. This is where I have my worries. For example: a consensus model on which transactions are valid, only works when the network is relatively big, otherwise someone with a big bot farm can take over the network.

And what does a blockchain add when there is no great incentive to create a big network of computers that want to build the blockchain?

What is your vision on Blockchain technology? Share your thoughts in the comments below!