What Is Bitcoin Core?

5 min read

Bitcoin Core is the free and open-source software that implements the Bitcoin protocol. It’s considered the reference implementation of Bitcoin, meaning it defines the protocol and acts as a standard for the network as a whole. It is the original and most widely used Bitcoin client. Bitcoin Core includes everything needed to participate in the Bitcoin network, whether by mining, transacting, or verifying transactions.

In this article, we explain what is Bitcoin Core and how it keeps Bitcoin running smoothly.

What Is Bitcoin?

Bitcoin is a decentralized digital currency that enables peer-to-peer transactions over the internet without the need for a central authority.

Learn more about bitcoin.

Is Bitcoin Core the Same as Bitcoin?

Bitcoin Core and Bitcoin are not the same as bitcoin is the cryptocurrency itself, while Bitcoin Core is the software that enables to use and distribution of this currency.

Who Started Bitcoin Core?

Satoshi Nakamoto didn’t originally refer to the software as “Bitcoin Core.” The term “Bitcoin Core” emerged later to distinguish between the original Bitcoin client and other software that emerged as the ecosystem grew. When Satoshi released the first version of the Bitcoin software in 2009, it was simply called “Bitcoin,” and it served both as a wallet and as the network’s node software.

Many other implementations of the Bitcoin protocol exist such as Bitcoin Knots, btcd, and bcoin. Despite differences, all implementations must agree on core features to maintain consensus.
Many other implementations of the Bitcoin protocol exist such as Bitcoin Knots, btcd, and bcoin. Despite differences, all implementations must agree on core features to maintain consensus.

Bitcoin Core is thus the continuation of the original client Satoshi worked on, now maintained and developed by a group of contributors from around the world.

What Does Bitcoin Core Software Do?

Running Bitcoin Core means you are operating a full node, which includes validating transactions, maintaining a copy of the entire blockchain, and relaying transactions to other nodes. 

Learn more about full nodes.

The main functions of Bitcoin Core include:

  • Validation: It validates transactions and blocks according to the Bitcoin protocol rules without relying on third parties. 
  • Wallet Functionality: Although primarily a node software, Bitcoin Core also includes a wallet functionality that allows users to send and receive bitcoin.
  • Mining Support: It supports bitcoin mining, though most miners nowadays use specialized mining software that can work in conjunction with Bitcoin Core for block validation.
  • Network Relay: Bitcoin Core relays transactions across the Bitcoin network, helping to propagate transactions and blocks.

Image showing the wallet functionality of Bitcoin Core

Bitcoin Core is open-source code meaning anyone can view, comment, or propose changes to the code. You can examine the code on GitHub.

You can download the latest Bitcoin Core version here.

Can I Earn Bitcoin With Bitcoin Core?

Although you can technically mine Bitcoin with Bitcoin Core by integrating it with a personal mining setup, it’s not an efficient solution for large-scale or profitable mining.

Learn more about bitcoin mining.

Originally, Bitcoin Core included a mining function that individuals could use to mine Bitcoin directly on their computers. However, as Bitcoin mining has become more competitive and specialized, this method has become largely impractical for earning rewards.

Who Controls Bitcoin Core?

The maintenance and development of Bitcoin Core is a collaborative effort from volunteer contributors called Core developers. There are no qualifications or restrictions to being a Core developer.

Core developers are not a centralized group of people. There is no leader or project manager who instructs developers on what to build.
Core developers are not a centralized group of people. There is no leader or project manager who instructs developers on what to build.

The primary maintainer role involves managing the GitHub repository, reviewing code submissions, and coordinating releases. In addition to the core maintainers, there’s a wider community of contributors who submit patches, improve documentation, find bugs, and suggest features.

Bitcoin Core version 26.0 was released in December 2023, containing experimental support for the “v2” transport protocol. 

Although anyone can propose changes, not all proposed code changes are immediately integrated into Bitcoin Core. Instead, the community intensively reviews and discusses each proposed change. Anyone can participate in these discussions and the decisions are settled by consensus. This model ensures that Bitcoin Core development is not controlled by any single entity but rather by the consensus of the community. 

Once a change has received acceptance, a few individuals who serve as maintainers of the code integrate the changes. These individuals are trusted by the community not to arbitrarily integrate code that has not been approved by the community.

If maintainers breach their trust, they will not compromise anyone’s existing node and the old Bitcoin Core code can be easily restored by ignoring the malicious changes. Thus, the role of Bitcoin Core maintainer carries respect but very little power or influence.

Does Bitcoin Core Control Bitcoin?

Bitcoin operates with various software implementations, not just Bitcoin Core, allowing node operators to choose their preferred version. These different implementations interact with one another to form a single, cohesive network, similar to how different internet browsers all access the same internet despite their differences.

Despite the variety, all implementations must adhere to core rules for transaction and block validity to maintain consensus across the network. Bitcoin Core, being the original and most popular, serves as the reference for others, setting the standards and guiding the development of alternative versions.

Why Run Bitcoin Core?

Running Bitcoin Core enhances your privacy and security as well as strengthens the network. There are several benefits such as:

  1. Increased Privacy: Using Bitcoin Core allows you to verify your own transactions without relying on third-party services. This enhances your privacy by not disclosing information about your transactions and balances to others.
  2. Network Strength and Security: The more full nodes there are, the more decentralized and secure the network becomes. Each node acts as an authority on the validity of transactions and blocks, making it harder for malicious actors to compromise the network.
  3. Empowerment and Sovereignty: Running your own node gives you more control over your transactions. It aligns with the ethos of self-sovereignty that is central to Bitcoin.
  4. Supporting the Ecosystem: Nodes help new users sync their software faster and more securely, and they contribute to the overall health and efficiency of the network.

Key Takeaways

  • Bitcoin Core is the most popular software used to connect to the Bitcoin network and run a node.
  • Bitcoin Core is open source software, meaning anyone can view, copy and propose upgrades.
  • Changes to Bitcoin Core only occur with consensus from the network.