What is a Bitcoin Full Node?

Are you someone who wants to help support and be a part of the Bitcoin Network? If so, one way you can go about doing this is by running your own full node. This article will explain what a Bitcoin full node is and the benefits it will bring by using it.

What is it?

A ‘full node’ is a program that authenticates transactions and blocks. A majority of them aid the network by accepting transactions and blocks from other nodes, validating them, and then relaying them to additional full nodes.

There is a crucial difference between a full node and a regular node. A standard node is any computer that connects to the Bitcoin Network. A full node is one that verifies all of the rules and regulations of Bitcoin. The most notable software implementation of full nodes is the third Bitcoin client, Bitcoin Core (formerly Bitcoin-QT).

Most full nodes serve lightweight clients by permitting them to transmit their transactions to the network. Moreover, they notify the clients when a transaction affects their wallet. Should there not be enough nodes performing this function, then the clients won’t be able to connect via the peer-to-peer network. In lieu of this, they will have to use centralized services.

A great number of people and organizations often volunteer to run full nodes by using spare computing and bandwidth resources. However, Bitcoin’s growth needs the involvement of more volunteers in order to achieve that development.

Consensus rules

For a full node to be a ‘full node’, it needs to download every block and transaction. Then, it needs to check them against Bitcoin’s consensus rules. Here are just a handful of examples of the consensus rules:

Blocks may only produce a certain number of blocks. This is otherwise known as ‘controlled supply.’ Currently, the count is 12.5 BTC per block.
Transactions need to have the correct signatures for the Bitcoins that users are spending.
Transactions/Blocks have to be in the correct data format.
Within a singular blockchain, a transaction output cannot ever be subject to double-spending.

If a transaction or block were to violate the consensus rules, then it will experience rejection. This happens even if every other node on the network sees it as valid. This is by far the most important characteristic of full nodes: they will always do what is right. No matter the circumstances at present, they abide by the rules.

For full nodes, miners actually possess some limit to their power. They are only able to either reorder or remove transactions and only by spending a lot of computing power. A powerful miner can execute attacks, but they are unable to completely change or seriously damage Bitcoin.

Nodes that go by different consensus rules are using two different networks/currencies. Altering any of the consensus rules requires a ‘hard fork’, which could create a new currency and have everyone move to it. A hard fork is essentially a divergence in a protocol that makes previously invalid blocks/transactions into something legitimate.

Policy vs. Consensus

Consensus rules are separate from policy rules, which specify how a node or minor prioritizes or dissuades certain things. Policy rules are open to easy changes and different nodes can possess different policy rules. Since full nodes must use the same consensus rules if they want to remain compatible, creating a full node from scratch is both difficult and dangerous.

For this reason, everyone who wants to run a full node should use software drawing from the reference client. This is the only client that will behave correctly.

Downloading & Storing

At the basic minimum, a full node must download every transaction that ever took place. This also includes all new transactions and all of the block headers. In addition, full nodes must store information regarding every unspent transaction output until it’s time to spend it. By default, full nodes are pretty inefficient. This means that they download new transactions at least twice and they store the entire blockchain forever. This is regardless of the fact that only the unspent transaction outputs are mandatory.

Costs, Risks, and Warnings

As one might expect, running a Bitcoin full node comes with its share of risks that lead to vulnerability. Whether or not you can help the network is entirely up to you and your strengths and weaknesses.

Below is a collection of costs and risks that you should be aware of.

#1 – Special Cases

Miners, companies, and privacy-conscious users depend on certain behaviour from full nodes they use. Because of this, they will usually run their own full nodes and take precautions. It would be wise to seek out assistance from the community when setting up your full node correctly. This way, you’ll be able to handle high-value and privacy-sensitive tasks. Be mindful of who gives you advice; seek someone who is qualified and reputable.

#2 – Secure your wallet

It’s entirely possible – and safe – to run a full node to support the network and store your coins in its wallet. However, you must be alert and take the same precautions you would when using a Bitcoin wallet. Such steps pertaining to securing your wallet include:

Being careful when using online services; always double check the URL you are using is the correct one.
Keeping only small amounts of coins in your wallet for everyday use.
Backing up your wallet.
Encrypting your wallet.
Making sure that your software is up to date.
Using the multi-signature feature to protect yourself against theft.

#3 – Minimum requirements

Full nodes on Bitcoin Core have specific requirements. If you try to run a node on considerably weak hardware, there’s a chance that it could work. Still, though, you will probably spend a lot of time dealing with various issues. If you are fortunate enough to meet the following requirements, you will have a node that’s easy to use.

Desktop or laptop is running recent versions of Windows, Mac OS X, or Linux.
There are 200 gigabytes of free disk space. It must be accessible at a minimum read/write speed of 100 MB per second.
It has 2 gigabytes of memory (RAM – Random Access Memory).
There is a broadband connection to the Internet. Its upload speed is of at least 400 kilobits (50 kilobytes) per second.
There is an unmetered connection or a connection with high upload limits.
Alternatively, there is a connection you regularly monitor to make sure it doesn’t exceed the upload limits. Full nodes on high-speed connections commonly use 200 gigabytes upload or more per month. Download usage must be around 20 gigabytes per month, plus 195 gigabytes when you first start your node.
6 hours a day for your full node to keep running. Keep in mind that you can do other things with your computer while the full node is running. More hours are preferable and you can run your node continuously.

Low-power mode

There is an important thing to note. Many operating systems nowadays (Windows, Mac, and Linux) enter a ‘low-power mode’ following the activation of the screensaver. This effectively slows or halts all network traffic. This is usually the default setting on laptops and all Mac OS X desktops and laptops. You should check your screensaver settings and disable the automatic “sleep” or “suspend” options. This ensures that you support the network whenever your computer is running.

#4 – Possible problems

There are an array of problems that are split into the following four categories.

Legal: The use of Bitcoin is prohibited or restricted in some areas. To put it bluntly, its legal status – along with other crypto instruments – varies from state to state. In fact, it’s either undefinable or changing in a majority of them. While most countries don’t make the usage of Bitcoin illegal, its status as money (or commodity) differs with varying regulations.
Bandwidth limits: There are some Internet plans that charge an additional amount for excess upload bandwidth that’s not in the plan. What’s more, some providers may cut off your connection because of overuse. To make matters worse, this will be done without warning. You should check whether or not your
Internet connection is susceptible to such limitations. Plus, monitor your bandwidth use so you can halt Bitcoin Core before reaching your upload limit.
Antivirus: There have been people who put portions of notable computer viruses into the Bitcoin blockchain. This data can’t infect your computer, but some antivirus programs will quarantine the data regardless. This will make it very difficult to run Bitcoin Core. This problem primarily affects computers that are running Windows.
Attack target: Bitcoin Core powers the peer-to-peer Bitcoin network. People who disrupt the network may attack Bitcoin Core users in ways that will change other things you do with your computer. This includes an attack that could limit your available download bandwidth.

Why use a wallet?

At this point, it’s apparent that full nodes are a useful piece of tech. Now, you might be beginning to ponder the potential usage of a full node wallet. “Why should I use it?”

Running a full node is pretty much the only way you can use Bitcoin in a trustless manner. You will know for sure about the system following the rules and also that no coins are experiencing double-spending. Furthermore, no inflation occurs outside the schedule and it abides by the rules that the system needs in order to work. Full nodes are – at this point – the most private way to utilize Bitcoin, as no one learns which addresses belong to you.

On the whole, full nodes are probably the most secure way to use Bitcoin. There are multiple reasons as to why using a full node wallet would be beneficial for you:

Economic strength

This is definitely the most important reason to run a full node. However, it can be especially difficult to grasp.

As previously mentioned, full nodes reinforce the consensus rules no matter what. Lightweight nodes, on the other hand, don’t do this. They basically do whatever the majority of mining power says. So, if most of the miners got together to boost their block reward, lightweight nodes would blindly go along with it. Should this happen, the network will split. These nodes – and also full nodes – will end up on separate networks, using different currencies. People who use lightweights are unable to transact with people using full nodes.

If all businesses and many users are utilizing full nodes, then the split isn’t necessarily critical. This is because users of lightweight clients will notice that they can’t send/receive bitcoins with those they typically do business with. Consequently, they will stop using Bitcoin until the malicious miners are overthrown.

At the same time, let’s assume everyone on the network uses lightweights in this situation. This means that everyone will continue to be able to transact with each other. This could lead to malicious miners essentially hijacking Bitcoin.

Therefore, for the sake of Bitcoin’s survival, it’s critical that full nodes are what back the Bitcoin economy, not lightweight nodes.

Privacy

Downloading the blockchain is arguably the most private way to operate a wallet. Any other lightweight solution will leak information about which addresses are yours. Electrum servers will know which addresses are yours and can connect them. Regardless of bloom filtering, which is a data testing mechanism, lightweight nodes drawing from BitcoinJ (the Java implementation of the Bitcoin protocol) don’t provide much privacy against nodes directly connecting to the wallet.

While financial privacy isn’t a requirement for some use cases, it’s still an important reason to use a full node wallet.

Security

Lightweight nodes are usually tricked into temporarily accepting transactions or blocks that aren’t valid. This could cause potential financial damage, especially for websites that process Bitcoin transactions. Full nodes, by contrast, provide the maximum security possible. All businesses should use them, and the same goes for regular users when it’s convenient.

Network services

Full nodes will often provide various services to other network participants. This is especially important when it comes to lightweight nodes. These services will typically include:

Filtering transactions and blocks on behalf of lightweight nodes. This is so that lightweight nodes don’t need to download every transaction ever made on the network to recover their own transactions.
Serving historical full blocks to nodes that have been offline for a certain length of time.
Transferring brand new transactions from users to miners.
Broadcasting newly-distributed blocks from miners to other nodes.

These services are generally only useful for full nodes that are listening on port 8333. The more full nodes that accept incoming connections there are, the more users the Bitcoin network is able to support. So, what if there is a shortage? Well, then it leads to the creation of lots of archival nodes by cheaply renting VPS or AWS space.

Are you ready to set up your Bitcoin full node?

Research and helpful advice is key to figuring out how to run your own full node. Now that you have obtained basic knowledge, you can begin the procedure by heading over to Bitcoin.org where they will take you through each and every step. And if you want to understand more about this topic, I'd recommend a book called - 'Blockchain, Crypto and DeFi: Bridging Finance and Technology' - and it's available on Amazon here https://amzn.to/3ZWxKCu