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Blockchain architecture and JavaScript

Blockchain architecture and JavaScript

Why (and why mot) using JavaScript

Many of my students wishes to create their own blockchain applications. Many of them came from app and web development background, and while they are still highly motivated to learn how the blockchain itself works, their main goal is not purely academic. They want to see a product in action.

When catering for such students, it’s important to adjust the course material to their own background and goals. Mainly it means to provide them with as many JavaScript tools as possible, as it’s the main engine behind many modern websites and apps.

Yet, adjusting the course shouldn’t come at the price of marginalizing the blockchain architecture itself. At the end of the day, the thing that separates such a course from millions of other web/apps development courses is just it – the blockchain.

Bearing this in mind should be a at the heart of every decision taken when creating and conducting such a course. And there’s a very little place for compromises.

This stunt approach led me to prefer teaching the students using more general programming language (mainly, python) while shy away almost completely from using JavaScript, which is fundamentally flawed for teaching protocols such as Bitcoin and the blockchain.

However, when done properly, a substantial part of the Bitcoin protocol can be explained, examined and tested using JavaScrips. And it’s important to develop the proper toolbox of JavaScript codes for that purposes.


// This code represents a possible approach for teaching Keys
// using JavaScript. 
// Pay attention that even while still using a JS library such as bitcore.js
// The code still follows all the steps defined in the developers documentation. 

bitcore = require("bitcore-lib");

privKey = bitcore.PrivateKey.fromString("8c5e5b37ebf1e7a274b9dff4910f9a2004868897f7d845802b77a1b245c26bc7");

pubKey = "04" +
        privKey.publicKey.point.x.toBuffer().toString("hex") +

pubKey = new Buffer(pubKey, "hex");

hashedPublicKey = "00" + bitcore.crypto.Hash.sha256ripemd160(pubKey).toString("hex");

hashedPublicKey = new Buffer(hashedPublicKey, "hex");

checkSum = bitcore.crypto.Hash.sha256sha256(hashedPublicKey).toString("hex").slice(0,8);

checkSum = new Buffer(checkSum, "hex");

binAddress = hashedPublicKey.toString("hex") + checkSum.toString("hex");

binAddress = new Buffer(binAddress, "hex");

address = bitcore.encoding.Base58.encode(binAddress);


When to use JavaScript

The decision of when, and how to use these codes should be based on 2 main variables.

  1. What the students need to know.

The first one refers to the main reason the students came to the course. The more interested they’re in the blockchain itself, the more they can gain by working with languages such as Python/C++/go etc’. On the other hand, if applications is what they want to create, they can benefit the most by using JavaScrip.

Using JavaScript can be a great experience for them as they’ll both learn how to incorporate many robust libraries into their projects, but (maybe even more important), they’ll understand many of the limitations that surrounds JavaScript and its impact when creating a blockchain app. Limitations such as working on the client side, storing keys, accessing ssl, working with large numbers etc’.

2. What the students already know.

This one is quite simple, what’s the student background. If the student is more competent in JavaScrip, he/she might benefit more from adhering to JavaScript instead of learning another programming language.


Can blockchain really be taught using just JavaScript?

I’m still checking it.

I’m trying to migrate as many of the codes that are used for teaching the blockchain itself from Python (most can be found here) to JavaScript.

In the next few posts I hope to provide a more detail accounts on this project, in the hope that it might be more helpful to future students.