Blockchain is so popular today; everybody knows that cryptocurrencies operate on it, but not many of those speaking about it really understand what it is and how one can be created. This blockchain tutorial unravels the puzzle of the innovative technology for laypersons by telling about its core components, the basic principle of consensus on which it works, and explaining its core types existing to date. It also dwells on the programming languages suitable for creating a product of your own to respond to the questions “how to become a blockchain developer?” and “how to program a blockchain?” Here you will find a range of valuable answers to questions about the essence of its operation and clarify where to learn blockchain coding from the best professionals.
The advent of blockchain is indispensably connected with that of Bitcoin, as the BTC system created in 2008 actually became the first sample of the kind. Thus, anyone starting the research on how to program blockchain has to deal with Bitcoin coding as the first reference point. However, it would be unfair to connect this blockchain developer tutorial only with BTC, as the history of electronic cash as such dates back to the 1980s, much longer ago than BTC creation. David Chaum was the first to propose and realize a model for e-cash protocols on the principles of anonymity and accountability. Chaum introduced two cryptographic operations (blind signatures and secret sharing) to achieve these two aims in his 1984 seminal paper; based on these technological features, the e-cash scheme Chaum, Fiat, and Naor (CFN) emerged soon afterwards. The CFN also introduced the security reduction technique by means of which a certain algorithm’s security is ensured via the use of another cryptographic problem as comparison.
Another step forward in the technology’s development was made by Adam Back in 1997 via the introduction of the hashcash concept; it operated as a proof of work (PoW) system to control e-mail spam. The idea behind hashcash was very simple; legitimate users sending e-mails had to compute a hash as a proof of spending a reasonable minimum amount of computing resources for sending the e-mail. Though computing a hash as PoW takes time and resources of one’s computer, it does not hinder one’s ability to send e-mails because it is presumed that a regular user (not a spammer) sends a relatively small number of messages per day. Verification of the computed hash is done by the e-mail recipient. This concept laid the basis of the Bitcoin mining process. In parallel to Back, the overall idea to use computational puzzles as hashcash was also explored by Cynthia Dwork and Moni Naor in 1992; these two mathematicians coined the term “pricing functions” to denote the hard functions that had to be computed before being granted access to a resource.
Based on the hashcash concept, the first b-money saw the world in 1998, introduced by Wei Dai. The system represented a peer-to-peer network with nodes containing their own lists of transactions. Almost a decade later, a similar idea was implemented by Nick Szabo as BitGold; the same year, in 2005, Hal Finney combined b-money with hashcash to invent the concept of cryptographic currency as the world knows it today, but with one reservation – it was a system relying on a centralized trusted authority.
Why did these systems not work out? The reason for all these projects’ short-lived existence was a range of issues with disagreement between modes, the use of trusted timestamping, and reliance on a centralized trusted third party. The first example of an unbelievably successful blockchain is thus Bitcoin – the first effort to create a network based on distributed consensus without a centralized controller.
To learn blockchain development, you need to have a clear idea of what it is first. So, let’s consider several technical definitions of the concept:
All blockchain tutorials have to include the description of its basic elements, as without them, it would be hard to understand how the system functions. Here are some of them:
All beginning blockchain programmers have to get acquainted with the concept of distributed consensus, which is the core of any programming in the blockchain. This mechanism was created to provide a means of agreeing to a single version of truth by all peers in the particular network. In this technology, all types of consensus fall into two types: the proof-based (or leader-based), Nakamoto consensus and the Byzantine fault-tolerance based consensus. The former presupposes the network’s leader to have the final word in the process of transaction validation, while in the Byzantine consensus, the round of votes validates it. It is simply impossible to create a blockchain without a complete understanding of this concept as it fuels the process and allows blockchain to stand apart from any other existent technology today. Here is the list of currently used consensus algorithms:
Now that you have got acquainted with the nuts and bolts of distributed consensus, our blockchain development tutorial proceeds to the types of systems to choose from.
Knowledge on how to develop blockchain would be incomplete without understanding its various types existing in today’s technology. Before coding blockchain, you should be clear about its goals and functions; otherwise, you risk ending with a product irrelevant to your needs and having no business value.
Now that the types of blockchain are clarified, let’s deal more closely with the blockchain software development; here is more information on how to code a blockchain. The variety of blockchain programming languages exist to date and can be used for making new systems. Some of them are universal, also used for other web/mobile software development, while others are unique for this technology and are non-applicable to other spheres. Let’s discuss them in more detail – below you will find the exhaustive list of blockchain coding languages available for programmers as of 2018.
What language is blockchain written in? That question is not easy to answer, as a variety of systems operates on different programming languages, which determine their functionality, security, flexibility, and value. Here is more information on currently available range of blockchain languages.
Though C still exists (and C programmers are like dinosaurs – rare and very precious), C++ is a much wider used programming language. Unlike the process-oriented C, C++ was developed as an object-oriented language that packs data and its functions into objects. When applied to blockchain programming, C++ offers numerous coding benefits such as effective resource management and robust memory control. Given the system’s specifics of systematic and simultaneous interaction of multiple nodes, C++ enables the creation of applications that both coordinate between multiple end points and process interactions quickly. For this reason, C++ is the language of Bitcoin, Ethereum, and Ripple.
Programming with Python is simple and minimalistic, similarly to this programming language’s philosophy. Python has for a long time enjoyed popularity among software and web developers and now gains popularity as a language for blockchain programming. The reason for Python’s immense popularity among such systems’ creators is that one can perform multiple tasks with only one command, which makes the creation of data blocks and their linkage much easier. While Python is definitely unsuitable for writing decentralized apps or holding ICOs, it is part and parcel of almost every existing system in the form of their public tools.
The programming language of the Web, Java has also found its application in the blockchain programming area. It turned out most effective in creation of simple, immutable networks, which ensures the continuity of blocks in them and prevents their forgery. Moreover, since Java is mostly used for website design, it makes it easy to link blocks of information. Thus, creation of the relationship between data and sending that data block to other users is easy with Java. Finally, the Java advantage for programming is its flexibility and universality: it can run on almost any computer upon easy and quick installation of JRE or the Java runtime environment.
Given that JS is a popular loosely-typed scripting language for the Web, highly universal and supporting anything from HTML/CSS pages to complete UIs, it has also found an application in blockchain development. One of its first uses in the sphere was the Lisk project – it enables programmers to build and deploy applications of this kind in JS.
While cryptocurrencies are complex, the blockchain is not, and a simple network with the proof-of-work consensus algorithm may be easily created in PHP. To do so, the programmer should download the blockchain source code and run php tests/simplechain.php from the command line. The output resulting from this operation will be a simple 3-block product. For its validation and test of its immutability, the PHP programmer may run the command php tests/hackchain.php.
Ruby is an excellent language for blockchain development, since it is versatile and easy. It allows quick customization to individual requirements and what is more, it is totally free on a global scale. Thus, many programmers select Ruby as their preferred language because of its availability, simplicity, variety of functions, and affordability.
Created specifically for the blockchain coding by Russel O’Connor, Simplicity indeed corresponds to its name – it is the easiest programming language for such products’ creation. The language is meant for designing smart contracts for the network and takes such crypto-languages as Bitcoin Script and EVM one step further by offering improved safety and automated cost calculation via static analysis. Though the language is quite new and not tested widely thus far, its prospects are optimistic because of the improved functionality, simplicity, and safety it offers.
Solidity was offered by Gavin Wood for high-level contract-based programming for a variety of decentralized platforms. This language is very simple, especially for programming newbies, since it offers many explicit explanations of how the code works. The major benefit of using Solidity for such technology’s creation is that it may be quickly mastered by people not familiar with other languages of programming, who may create their own networks without in-depth technical knowledge and experience. These features make Solidity ever more popular in the discussed technology development field, and it’s now a single programming DSL supported in multiple networks (Ethereum, Ethereum Classic, Cardano).
GO (or Golang in full) is an open-source language given away by the Google team for public use in 2012. It is a bit harder than other programming languages in terms of distributed systems’ development, but it can be successfully used for coding of cryptocurrency. The benefits of GO include absence of runtimes, availability of powerful libraries distributed in the form of packages, concurrency enabled by GO primitives and routines, and easy adaptation to multi core architecture and expanded memory. As a result of Google team’s effort, GO is a successful sample of user-friendliness and simplicity of popular languages like Python and JS combined with outstanding performance and security of more complex languages like C.
No blockchain programming tutorial can do without discussing Bitcoin as the first example of this technology type. So, what is Bitcoin written in? Interestingly enough, the Bitcoin system is void in different languages of programming. Experts note that the major part of BTC is written in C++, while some popular BTC agents still operate in Python and Java. Thus, there is no single Bitcoin language in existence.
An innovative specification and general-purpose programming language of Skycoin, CX is a new word in the world of programming languages. This language can serve as a contractual digital intermediary enabling simple and complex functions; it employs robust error reporting and offers enough flexibility and versatility to gain popularity in this area. Another benefit of CX is its ability to create expansive use-cases of digital technology through smart contracts and even more advanced technologies. CX is based on GO, which makes it resistant to arbitrary code execution and gives it advanced security.
As you can see from the list above, numerous languages are used to create distributed systems and their multiple tools and agents, while in some systems, several languages of programming are used at once. Why is that needed? Why not select one language to do the task? Here are some reasons:
Isolation to ensure determinism. All hash functions should be deterministic to ensure that all transactions are conducted in the same way, without deviations, and lead to predictable outcomes. This is achieved via isolation of smart contracts and transactions from non-deterministic elements of the network.
Despite so much available information on this technology, even technically experienced people sometimes find it hard to explain it in simple words. We think that visuals are better than a thousand words, so here is the blockchain example code for better understanding of the concept.
Here is a blockchain code example; it contains data about the message, its private and public key, and the unique signature including the information about the sender and recipient. These are usual components of a transaction.
All systems of this kind need block creation to take place continuously, which ensures their operation and development, keeping the system alive. Hence, we have decided to include some background data on the block accumulation into this blockchain code tutorial.
The first step involves the start of a transaction by the node. This takes place after a node signs a transaction with its private key. After that, transaction is flooded (that is, spread) with the help of the Gossip proto (in Bitcoin) or a similar mechanism to peers who validate the transaction based on the predetermined set of criteria. One transaction should be validated by several nodes. Upon the transaction’s validation, its inclusion into the block takes place; the block is then again propagated to the network of peers, which signals about the transaction’s confirmation. This new block becomes a part of the ledger and links cryptographically with the hash pointer to the previous and the next blocks in it. Transactions get reconfirmed with every new block’s creation; in the BTC system, six confirmations are the minimal requirement for the transaction’s finalization.
With such an immense (and rising) popularity of blockchain and its increasing use for enrichment, more and more programmers ask themselves, “how to become blockchain developer?” Without any doubt, the demand for blockchain dev is going to rise steadily in the near future, which is a guarantee of high salaries and demand in the labor market. So, here we cover some steps of blockchain developer training that you should know for entering this professional area.
Many of you wonder “how to learn blockchain programming?” There are several steps to become a successful programmer, and the first one is naturally learning some programming language. However, knowing the mechanics of tech development is not all you need; this is a complex innovative technology, and you cannot make a good product in case you do not understand its principles, philosophy, and mechanism. To clarify all that and get to the intermediate level of technical knowledge, we recommend the following:
A simple checklist for those who want to join the world of blockchain is as follows. You need to:
Now that you know what it is and why it is important, it’s high time to get familiar with the practical side of the issue – the ways in which blockchain may be created and brought to life with the functionality you need, fulfilling your pre-established goals. To achieve that, you surely need to take a blockchain developer course. At any programming course specializing in this tech area, you will get an answer to the question, “what is blockchain programming?” and will acquire basic blockchain developer skills. This is what you need most, as the rest is about creativity and innovation of your own authorship.
So, which blockchain programming course to take? There are so many offers online that one can get lost in the realm of options and pay money for a training session that he/she actually does not need. Let’s discuss the market offers in more detail to find out what you need for successful training.
No doubt, you will need to take some course to get the tech skillset and practical knowledge for such a system’s creation. So, where to start and how to learn that without significant investments?
Other highly recommended courses on how to become a blockchain engineer may be found in the free course sections of the Stanford University, Duke University, EdX, and NYU.
The final tip: you can always train with Space Doggos and CryptoZombies – these are two free training simulations for blockchain programming that do not require any investment and are risk-free for all users. Try yourself, see the results, and then proceed to creating a real product!
At present, the number of capable developers in this specialty across the globe ranges between 7,000 and 8,000 people – not that much for the global population of over 7 billion! However, this professional area is actively explored today, with more programmers migrating to blockchain development. Thus, by 2019-2020, the number of available developers may grow up to 100,000. Is there any sense for you to join that crowd? Let’s clarify.
At present, jobs in this field are very nicely paid; an experienced developer can claim up to $200,000 of annual pay, and he/she will get that money! An average salary of developers in the USA is $130,000, while general-purpose software engineers earn around $100,000. Even working as a freelance consultant, you can make $50-150 per hour. Whether it is a decent salary or not, it’s up to you to decide. However, the prospects for this specialty are highly optimistic, with the number of job offers rising day by day, and the demand projected to increase in the years to come.