How to Program Blockchain? Top Languages You Need to Know

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.

History of blockchain software development

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.

Blockchain coding: Generic Elements

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:

1. It is a decentralized consensus mechanism in which all users are peers with equal rights and they validate the transaction by reaching an agreement on its status;
2. It is a distributed shared ledger (we’ll discuss this concept in the section about its types below) of transactions. Unlike real-life ledgers that represent private databases held by private owners, a distributed and shared ledger has no owner and no chief administrator; it serves as the only source of truth for all participants;
3. It is a data structure using hash pointers instead of usual ones referring each new block of data to the preceding one, which guarantees continuity and a stable reference point for transaction validation.

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:

• Addresses are the individual identifiers of any transaction denoting senders and recipients of value. They represent a public key or are derived from it. While one user can re-use one address for several transactions, most users don’t typically do that to avoid being traced. Thus, a new address is usually created for every new transaction;
• Transactions are transfers of value from one address to another one within the system;
• Blocks are units of containing several transactions, the hash pointer of the previous block ensuring the chain’s consistency and uninterruptedness (as well as protection from blocks’ forgery), a unique timestamp, and nonce;
• Peer-to-peer network is the communication system within the technology in which all users can exchange messages;
• Scripting/programming language enables a variety of operations within the transaction. For the transaction to take place and be valid, its script has to contain commands for nodes activating the token transfer;
• Virtual machine is an extension of the transaction script enabling the Turing complete code in the form of a smart contract. It is needed because a transaction script is limited, while the virtual machine activates a greater range of functions. Not all blockchains possess this feature, but some widely known virtual machines include the Ethereum Virtual Machine (EVM) and Chain Virtual Machine (CVM);
• State machine is an alternative view of the blockchain because it works as a transition mechanism in which transactions and node verification modify a state from its initial form to the next one;
• Nodes are the users performing several functions in the system’s activity, such as proposing and validating transactions, mining for consensus facilitation, ensuring security, performing payment verification, validation, etc;
• Smart contracts are programs run apart from the blockchain and enabling certain business processes under the conditions fixed in them. Their benefits include flexibility and additional capacity, so more networks create the smart contract feature today.

Blockchain programming: the Concept of Consensus

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:

• Proof of Work (PoW). This is a classical form of consensus relying on the proof that enough computational resources have been spent on proposing a value for acceptance by the network. In other words, the user has spent enough hash power to produce a value that is recognized by other nodes. The Bitcoin and many other popular systems use this consensus algorithm, and it has proven highly effective against Sybil attacks;
• Proof of Stake (+ delegated PoS). This consensus is based on the assumption that a node has enough stake in the system; that is, he/she has invested enough into the system so that attacks on the system would be unfavourable for any of them. This concept was first introduced in the Peercoin and is expected in the Ethereum system in the near future. Delegated PoS is a technical innovation used in Bitshares; it allows nodes with a stake in the system to delegate transactions’ validation to other nodes via voting;
• Proof of elapsed time. This consensus protocol is used by Intel in the form of the Trusted Execution Environment (TEE). This system ensures the randomness of the leader election process with the help of guaranteed wait time;
• Deposit-based consensus. This consensus approach requires nodes to make security deposits in the system before they can propose a new block;
• Proof of importance. Applied in Nemcoin, this consensus type presupposes tracking of every node’s use and movement of his/her tokens to determine the level of this node’s trust and importance in the system, which in turn gives a different value to the node’s vote on transaction validation.

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.

Programming in Blockchain: Understanding Its Various Types

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.

• Public blockchain. Such systems are open and have no owners, with anyone wishing to take part able to join the network at any time and participate in the decision-making process. Participation may or may not be rewarded;
• Private blockchain. Such systems include only members of a certain closed group of people sharing the ledger among them;
• Semi-private blockchain. Some networks combine the features of private and public systems, with some parts owned by private groups and others – open to the public;
• Sidechains. These systems emerge when forking takes place and certain coins are moved from one network to another one. One-way pegged sidechains presuppose the burning of coins that are removed irreversibly, while two-way pegged sidechains allow movement of coins from one system to another one and back;
• Permissioned ledger. In such a network, all participants know and trust each other, so they use an agreement protocol instead of the distributed consensus to validate transactions;
• Distributed ledger. Here, the ledger is distributed among participants with records stored contiguously, not in sorted blocks (e.g., Ripple);
• Tokenized blockchains generate cryptocurrency via mining or initial distribution;
• Tokenless blockchains are not quite blockchains, since they do not include an integral component of value transfer. However, they still exist to enable network users to share some data among trusted parties.

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.

Blockchain Coding Language

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.

What language is blockchain written in?

This question is the gist of understanding programming of blockchain. According to experts, the generic programming language required for such type of systems is Turing complete language. However, with modern technology advancements, technology products of this type are enabled by a variety of new programming languages such as C/C++, Java, JavaScript, PHP, Python, Ruby, Go, Rust, C#, and Objective-C.

C/C++: The blockchain language

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.

Blockchain programming in Python

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.

How to code a blockchain in Java?

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.

How to code a blockchain in JavaScript?

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.

How to code blockchain in PHP?

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.

How to program a blockchain in Ruby?

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.

How to create blockchain in Simplicity?

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.

How to make blockchain in Solidity?

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).

How to code blockchain in Go?

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.

What language is bitcoin written in?

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.

CX – a blockchain programming language of new generation

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.

Why are many languages used?

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:

1. Safety. The concept of blockchains’ public availability and openness to anyone is fantastic, but it is also connected to potential security issues. Since the code is open for any person to view and test it for vulnerabilities, these networks have to be totally invisible, as a successful hacker attack may cost users all their belongings;
2. Resource management. Successful operation is impossible without keeping pace with the network demands (that typically grow exponentially). This may be done by handling remote and local queries;
3. Performance. Blockchains have to perform perfectly well to manage both simultaneous and non-simultaneous tasks properly. Some programming languages are good at enabling non-parallel functions, while others work with parallel ones much better. Thus the need to combine several languages in one network to achieve maximum performance;

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.

How to develop blockchain? A visual example

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.

Blockchain code example

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.

Tips to create blockchain: how are blocks accumulated?

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.

How to create blockchain blocks?

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.

How to Become a Blockchain Developer?

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.

1. Capture the basics of blockchain and its relevant terminology (discussed in detail above);
2. Clarify for yourself how the entire system works (it’s much better to test everything on practice by registering at some platform and buying some cryptocurrency to test the system’s functionality);
3. Learn the coding principles. Let’s stop here for more detailed review.

Learn blockchain coding

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:

• Reading the white paper of Satoshi Nakamoto about Bitcoin. Since he was the one to create and launch Bitcoin, and can be regarded as a forefather of blockchain, understanding what he meant to create and how he means it to function is a must;
• Studying a range of IBM resources about it. They have been compiled by true experts in the field, so you will find a realm of useful information in simple words to get to know the entire concept better;
• Microsoft Azure also offers a wealth of relevant, useful information for effective learning. You can find numerous articles and reports about Azure blockchain projects at Github to find out more about the practical side of its programming;

A simple checklist for those who want to join the world of blockchain is as follows. You need to:

• Know what this technology is, able to explain it in your own words;
• Understand its potential effect on your business and overall industry;
• Join a community of entrepreneurs, business people, and technologists shaping the modern technological trends;
• Determine the most important aspects of this technology for you.

Blockchain programming course

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.

How to learn blockchain programming

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?

• Our #1 recommendation is to look for courses at BlockGeeks. They offer a ton of useful training courses such as Cryptoeconomics 101, non-technical intro to blockchain, an introductory course to building a decentralized app, app development for Microsoft .NET, a basic Solidity course, and much more. The courses are moderately priced - $29 per month;
• Another authoritative resource to study with is Coursera. Here, you will find an introductory course on Bitcoin and Cryptocurrency Technologies, the IBM Blockchain Foundation of Developers, and the like. And that’s all for free!
• Udemy also offers numerous helpful courses on blockchain, covering the complete understanding of this technology, webinars teaching programmers how to become developers with Ethereum and Solidity, Ethereum Development Masterclasses, etc.

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!

Join the team of blockchain programmers

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.

Blockchain dev: how demanded is it?

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.

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