History Today: Eight Years of Block Size Wars, the Revelation of Blockchain's Checks and Balances Philosophy
On August 15, 2015, this day later became known as the "day the block size war broke out."Author: Jaleel, Jack, BlockBeats
Until today, block size remains one of the most discussed topics among blockchain developers. How much content a block can hold involves the hardware requirements of nodes, which in turn affects the decentralization of the entire chain. Different views on this issue have led to various consensus designs, and of course, many well-known forks. Looking back at the brief history of cryptocurrencies, the beginning of all this may be traced back to today, eight years ago.
On August 15, 2015, two early Bitcoin technical pioneers, Gavin Andresen and Mike Hearn, jointly announced on their blog that their new version of BitcoinXT would implement the BIP-101 proposal, which would activate directly without requiring a vote from miners. This day later became known as the "Day the Block Size War Erupted."
The Crossroads of Blockchain
Since the birth of Bitcoin in 2009, the Bitcoin community has been divided on several key issues. Among them, the debate surrounding the size of Bitcoin blocks has been the most intense. This controversy originated from the original design intent of Bitcoin. The mysterious founder Satoshi Nakamoto set a limit of 1 megabyte per block to prevent meaningless transactions and data bloat. However, as Bitcoin gained popularity, this limit began to feel restrictive, leading to network congestion and increased confirmation times. In fact, as early as 2013, core developer Jeff Garzik proposed doubling the block size to 2 megabytes, sparking initial discussions within the Bitcoin community about block size.
In 2015, the controversy escalated further. Developers advocating for larger blocks initiated the Bitcoin XT project, attempting to directly increase the block size to 8 megabytes.
On one hand, Gavin Andresen and Mike Hearn, the original developers who had deep communication with Satoshi Nakamoto, leaned towards raising the block size to 8 megabytes as a strategy to cope with the growing transaction volume. On the other hand, core developers like Greg Maxwell, Luke-Jr, and Pieter Wuille warned that excessive expansion could lead to fewer nodes being able to run full nodes, thereby reducing Bitcoin's level of decentralization. They even suggested that a hard fork could lead to chaotic splits in the network, and that endlessly pursuing larger blocks was not the best solution for scalability.
Meanwhile, 2015 also witnessed the birth of Ethereum. Its founder, Vitalik Buterin, although a staunch supporter of large blocks, focused his ideas on the Ethereum chain. He believed that the scalability of the chain should have no boundaries, and that all smart contracts and data should be included on-chain, while providing larger blocks and lower transaction fees.
This controversy subsequently evolved into a serious split within the Bitcoin community. Both sides engaged in multiple rounds of intense discussions about block size, but they could never reach a consensus. The block size war initially started as a debate about how the network should scale to handle increasing transaction volumes, but later transformed into a philosophical debate about the ultimate purpose of Bitcoin and the "political drama" surrounding the management of this open-source project.
In 2017, developers supporting larger blocks initiated a hard fork to create Bitcoin Cash (BCH), directly increasing the block size to 8 megabytes. This led to a formal split in the Bitcoin community into two factions. Supporters of smaller blocks continued to maintain the original Bitcoin blockchain, while supporters of larger blocks created a new Bitcoin Cash blockchain. Thus, the block size controversy resulted in the first and largest fork in blockchain history.
After the fork, both chains developed independently, and the block size controversy continued. Bitcoin maintained its block size at 1 megabyte, while Bitcoin Cash further expanded its block size to 32 megabytes in 2018. Ultimately, this block size war ended with the smaller block faction emerging victorious. However, winning one battle does not mean the war is over, as new BIPs continue to be proposed, and there remains much debate between the "small block camp" and the "large block camp."
BRC20, Ordinals: A New Battleground for Power Struggles
The Bitcoin Taproot upgrade inadvertently opened up a new design space, allowing users to inscribe arbitrary content on the blockchain. In 2023, the Bitcoin ecosystem gained some unexpected play styles, such as BRC20, ordinals, and Bitcoin NFTs. With the emergence of these play styles, new controversies arose and intensified, with many referring to them as another form of the block size war.
Firstly, the emergence of these play styles led to skyrocketing gas fees. From the miners' perspective, this is undoubtedly a good thing, as from the summer of 2021 to early 2023, Bitcoin block space was almost a wasteland, and miners' income was minimal. However, for those who cannot afford high gas fees, this is not a good thing. "I mainly onboard in Africa. They don't have the privilege like you to pay these high fees. They really need BTC, while you guys are just playing," wrote Bitcoin educator Anita Posch on Twitter.
More importantly, BRC20 and Bitcoin NFTs challenged the original 1M block size limit. The most notable example is the founder of the Meme NFT Taproot Wizards, Udi Wertheimer, who orchestrated the largest block and transaction in Bitcoin history, a nearly 4MB block size, referred to as "the largest Bitcoin block ever," which many criticized as an attack on Bitcoin.
Blockstream CEO Adam Back and Bitcoin Core developer LukeDashjr argued that this could cause the Bitcoin blockchain size to expand rapidly, significantly increasing the requirements for running full nodes, leading to a decrease in the number of full nodes across the network and a reduction in censorship resistance. At the same time, the unexpectedly large transactions and blocks could impact wallets, mining pools, browsers, and other ecosystem facilities, causing some facilities to malfunction, such as certain transactions failing to parse correctly. Additionally, mining pools or miners might choose not to download or verify these large transactions and blocks to reduce synchronization and verification times, posing security risks.
They even harshly criticized the Taproot Wizard's actions, stating: "This is an attack on Bitcoin. The Bitcoin block has a 1M limit, and the 4M data of Taproot Wizard is being put on-chain in the witness, bypassing the 1M limit for both blocks and transactions. If 4M is acceptable, then 400M is too! In this sense, this is not innovation; it is an attack on a vulnerability!"
Related Reading: "A Comprehensive Analysis of Bitcoin MemeNFTs: What Are the Bald Wizards Taproot Wizard Paying Tribute to?"
In response, Udi stated that he owns a large amount of BTC and that his actions are meant to make it stronger. Like anything that withstands pressure, what does not kill it makes it stronger. He wanted to prove a point: the vitality surrounding Bitcoin has stagnated, and he wanted to change that state, fully aware that if people like him truly posed a threat to Bitcoin, then Bitcoin should fail.
Looking at BRC20, although its popularity has declined compared to a few months ago, it still holds significant influence. Since April 23, 2023 (when BRC20 began trading), Bitcoin's UTXO set has expanded from 5 GB to 6.8 GB.
Bitcoin enthusiast Ajian (@Aurtrian Ajian) believes that the design of BRC20 has significant implications for the protocol's security, economics (scalability), and decentralization. Firstly, because it does not rely on UTXO, it cannot depend on the anti-double-spending mechanism inherent to UTXO itself. BRC20 is entirely based on the "first-come, first-served" principle of block transaction ordering; without this "first-come, first-served" as a final backing, it cannot prevent negative balances as a form of double spending.
However, there are also many supportive voices. Nic Carter, co-founder of investment firm Castle Island Ventures, mentioned that some Bitcoin supporters today refuse to use the network for new types of assets like Ordinal NFTs and BRC-20, which is a mistake. Considering the libertarian foundation of the Bitcoin movement, which can be traced back to economist Murray Rothbard and the cypherpunk culture of the 1990s, demanding scrutiny of these non-economic use cases is unreasonable.
Power Balance: Who Decides the Future of Bitcoin?
Behind these debates lies not only a technical divergence but also a deeper discussion about the purpose of Bitcoin and the philosophical ideas behind it. Governing a decentralized open-source project remains a challenge. What ultimately determines the future of Bitcoin? Developers? Miners? Nodes? The community?
We all know that Bitcoin has no CEO; its governance structure consists of users who pay transaction fees, miners who build the Bitcoin blockchain, and node operators who validate the transaction ledger. This decentralized structure somewhat ensures the security and decentralization of Bitcoin, but it also presents challenges for governance. The positions of miners are self-evident, primarily driven by incentives, as they choose consensus on Bitcoin's future based on the incentives they receive.
For core developers, German engineer, entrepreneur, and investor Michael believes that we can admire them and donate to them, but we must never view them as our allies. Because core developers are software developers. All developers inherently enjoy patching and improving code, adding new features, and removing old ones. We clearly need their work and should reward it. However, we must also supervise and critique their work, as we can never know exactly when and which core developers succumb to the "I Can Fix Bitcoin Syndrome," so we must assume they all do and distrust every line of code they write.
From the perspective of nodes and the community, the Bitcoin Improvement Proposal process seems to be an informal procedure. Less than 1% of Bitcoin users operate nodes, while 99% of Bitcoin users are "casual" users who temporarily hold Bitcoin in custodial accounts, completely detached from the discussion. If they do not operate nodes, are their opinions still important? This is an interesting question, but Bitcoin would argue that their opinions are not significant. The block size war has pitted 99% of Bitcoin users against the technical 1%, leading to a hard fork when some of the 99% became node operators.
People from various perspectives and backgrounds have unimpeded visions and expectations for Bitcoin. The "block size war" reveals the intense conflicts and intersections of technical viewpoints in the blockchain world. This debate not only reshaped the development trajectory of Bitcoin but also prompted many to realize that when building blockchain technology, careful consideration of various design purposes and strategies is essential. Finding consensus on core issues in future blockchain communities and fostering healthy competition along technological paths remains a long and arduous journey.
However, one thing is certain: the spirit and culture of Bitcoin will never wither due to disagreements within the community. Each of us is not only a witness to this history but also a participant deeply involved in it.
