How to build a blockchain from scratch in Rust

Rust is an excellent language for blockchains, where reliability and implementation are crucial. It is user-friendly, fast, reliable, and memory-efficient. Due to the benefits of blockchains technology and the rising need for it, this article attempts to guide you step-by-step on how to make blockchains with Rust. The Rust blockchains executed in this article are the most generic and basic.

What are blockchains?

A blockchain is a decentralized ledger of marketing across a peer-to-peer network, you can also feel of blockchains as a decentralized and inflexible database. A blockchain can be broken down fundamentally into several parts e.g Node, Transaction, Chain, Block, and the consensus protocol (proof of work, proof of stake, proof of history).

If you are anything like me, you understand by installation. Now the reason I’m writing this article is to give you a fundamental overview of how blockchains work by making blockchains with Rust.

Why blockchains are exciting?

While I’m personally not especially curious about cryptocurrencies or financial gambling in general, I discover the concept of decentralizing parts of our current infrastructure very attractive. There are many wonderful blockchain-based projects out there that desire to attack societal issues such as climate modification, social inequality, privacy, and governmental transparency.

The potential behind technology created on the concept of a secure, fully transparent, decentralized ledger that allows actors to interact without having to establish faith first is as game-changing as it appears. It will be thrilling to see which of the aforementioned ambitious thoughts will get off the ground, achieve traction, and grow going forward.

In short, blockchain technology is compelling, not only for its world-changing possibility but also from a technical standpoint. From cryptography over peer-to-peer networking to fancy consensus algorithms, the field has quite a few intriguing topics to dive into.

What is Rust?

Rust is a dynamically compiled language with a comprehensive type system and ownership idea that is extremely fast and memory-efficient. It allows designers to debug at compile time and can be used to power performance-critical services while providing memory and thread safety. Additionally, Rust has fantastic documentation, an easy-to-use compiler, and bonus tools like integrated package managers and multi- editors with capabilities like type inspection and auto-completion.

stops all crashes, and it’s intriguing because it comes preconfigured as being safe, just like Ruby, JavaScript, and Python. Because we cannot write wrong parallel code and you can never see a flaw in Rust, this is far more effective than C/C++. It means many other programming paradigms fast and accurately.

Writing a blockchains app in Rust

In this manual, we’ll make a very simple blockchains application from scratch using Rust. Our app will not be extremely efficient, secure, or robust, but it will allow you to comprehend how some of the basic ideas behind widely known blockchains systems can be implemented simply, presenting some of the concepts behind them.

We won’t go into every element of every concept, and the execution will have some serious shortcomings. You wouldn’t like to use this project for anything within miles of a show use case, but the plan is to make something you can play around with, apply your thoughts, and examine to get more familiar with both Rust and blockchains tech in general.

The emphasis will be on the technical part — i.e., how to execute some of the ideas and how they play together. We won’t describe what blockchains are, nor will we touch on consensus, mining, and the like beyond what’s required for this tutorial. We will mostly be involved with how to put these thoughts, in a simplified version, into Rust code.

Also, we won’t make a cryptocurrency or similar system. Our design is much simpler: every node in the network can add data (strings) to the decentralized ledger (the blockchains) by mining a valid block locally and then broadcasting that block.

As long as it’s a good block (we’ll see later on what this implies), each node will count the block to its chain and our selection of data become part of a decentralized, indestructible, tamper-proof (besides that all notes shutdown in our case) network!

This is a quite simplified and somewhat artificial design that would run into efficiency and robustness problems rather fast when scaling up. But since we’re just doing this activity to learn, that’s fine. If you make it to the end and have some motivation, you can open it in any direction you want and maybe make the next big thing from our paltry starts here — you never know!

How to build blockchains with Rust?

Before moving with the steps of blockchains development, confirm you have installed Rust in your system.

Execute the block struct

First make source files, namely, “block.rs" and “main.rs".

In the block.rs file, determine the following properties we require within the block struct.

Execute block constructor and debug

Write the following codes to execute the block constructor.

Next, execute the debug formatter for the block using the following:

codes: Now, go to the “main.rs" file and write the following codes:

Make a trait named hashable in a new file, hashable.rs, and conduct the following n ncodes:

Execute Hashable on block

Now, let us execute the bytes function on the already made block struct by writing a new “simple" implementation block.

Make a blockchains struct

Make a new file and name it “blockchains.rs", within which you have to make your new blockchains structure.

Now, add its field, which is a vector of blocks.

Mining

To complete our blockchains-related logic, let’s execute our primary mining scheme.

When a new block is made, we call mine block, which will return a nonce and a hash. Then we can make the block with its timestamp, the given data, ID, last hash, and the new hash and nonce.

We spoke about all of the overhead fields, excluding the nonce. To describe what this is, let’s look at the mine block function:

After declaring that we’re about to mine a block, we set the nonce to 0. Then, we create an infinite loop, which increments the nonce in each step. Inside the loop, besides logging every 100000’s iteration to have a rough improvement indicator, we calculate a hash over the data of the block using calculate hash, which we’ll check out next.

Then, we utilize our hash_to_binary_representation helper and review whether the calculated hash adheres to our test standards of beginning with two zeros.

If so, we log it and return the nonce, the incrementing integer, where it occurred, and the (hex-encoded) hash. Otherwise, we increase nonce and go again.

We’re desperately attempting to find a bit of data — in this case, the nonce and a number, which, together with our block data hashed using SHA256, will give us a hash beginning with two zeros.

We require to record this nonce in our block so other nodes can confirm our hash since the nonce is hashed together with the block data. For instance, if it would take us 52,342 iterations to figure a fitting hash (starting with two zeros), the nonce would be 52341 (1 less, since it starts at 0).

Let’s glance at the utility for actually making the SHA256 hash as well.

This one is rather straightforward. We build a JSON representation of our block data using the existing nonce and put it through sha2‘s SHA256 hasher, returning a Vec.

That’s all of our blockchains logic executed. We have a blockchains data system: a list of blocks. We have blocks, which point to the last block. These are needed to have an increasing ID number and a hash that adheres to our rules of mining.

If we request to get new blocks from other nodes, we validate them and, if they’re OK, add them to the chain. If we get a full blockchain from another node, we also validate it and, if it’s longer than ours (i.e., has more blocks in it), we return our chain with it.

As you can guess since every node executes this exact logic, blocks and the agreed-on chains can propagate through the network fast and the network assembles to the same state (as with the aforementioned error managing limitations in our simple case).

Blockchains verification

Add the following procedure to the blockchains struct within blockchains.rs to demonstrate the blockchains.

Why use Rust for blockchains development?

Since the emergence of blockchains as a decentralized digital ledger, their use cases, and real-life applications have been on the increase. From supply chains to digital voting systems and asset management, blockchains are a technology that can be integrated into different parts of our life. The possibility it holds is immense, thanks to which many companies are adopting blockchain-based applications and software to make themselves ready for a web3-compatible future. As a consequence, more recent blockchains protocols are also emerging.

Rust delivers free abstractions and, by default, adheres to the most useful practice development and innovation principles. It is interoperable with C and C++ and is a user-friendly programming language. Rust is, hence, extremely reliable, memory-efficient, and fast. Additionally, Rust lacks a trash collector. Therefore, there won’t be any runtime indeterminism carried on by the language.

Conclusion

In this tutorial, we made a simple, quite limited, but performing blockchains application in Rust. Our blockchains app has a consensus, very basic mining scheme, and peer-to-peer networking in just 500 lines of Rust.

Most of the simplicity is to gratitude to the fantastic libp2p library, which does all the heavy lifting in phrases of networking. As is always the point in software engineering tutorials, for a production-grade blockchains application, there are many more things to consider and get right.

However, this activity sets the scene for the case, describing some of the basics and leading them off in Rust, so that we can continue this journey by examining how we would go about creating a blockchains application that could be used in practice with a framework such as a Substrate.