Discussions about Bitcoin's next upgrade have been ongoing, but as of December 2024, the community has yet to reach a consensus on whether to upgrade, what problems the upgrade should address, or what functionalities it should introduce. The debate remains polarized, resembling a political stalemate.
In this deadlock, several interesting phenomena have emerged:
These phenomena highlight that the topic of upgrades is highly popular within the Bitcoin community. However, they also reveal that many community members lack a comprehensive understanding of the complete process of a Bitcoin upgrade. Additionally, there is limited awareness of how innovative cryptographic tools can enhance Bitcoin's potential.The core purpose of this article is to break through this information asymmetry, align everyone’s understanding, and facilitate deeper discussions on the topic.
This article aims to define Bitcoin upgrades, trace historical developments to identify certain patterns, analyze current upgrade proposals, and provide readers with key takeaways. By presenting this information, the goal is to equip readers with a solid foundation in understanding the concept, history, and progress of Bitcoin upgrades, thus enabling more informed discussions and contributing to the eventual formation of community consensus.
The article strives to present facts objectively. However, as the author is a developer in the Bitcoin ecosystem and envisions greater possibilities for Bitcoin, certain viewpoints will be explicitly expressed on specific topics. Readers are encouraged to discern these perspectives critically.
Bitcoin’s whitepaper defines a protocol that operates a blockchain network composed of thousands of nodes following the Bitcoin protocol.
These implementations, or clients, come in various versions, with Bitcoin Core being the most widely used client, as shown by data from bitnodes.
Thus, the Bitcoin Core maintainers (referred to as Bitcoin-Core-Devs ) have significant influence over Bitcoin’s development.
Bitcoin node software consists of multiple modules, and upgrades are defined through Bitcoin Improvement Proposals (BIPs). When discussing Bitcoin upgrades, it usually refers to consensus protocol upgrades—modifications requiring agreement among the majority of the network’s nodes to avoid forks.
As illustrated below, Bitcoin’s consensus protocol modules and related BIP proposals are of particular interest in upgrade discussions.
According to statistics from the Bitcoin GitHub repository , development activity is vibrant. However, most changes are unrelated to the consensus protocol and thus do not attract widespread attention.
Per BIP-123, consensus protocol upgrades are classified into Soft Forks and Hard Forks:
Feature | Soft Fork | Hard Fork |
---|---|---|
Compatibility | Compatible with old nodes | Incompatible with old nodes |
Network-wide Update | Not always required | Required |
Examples | SegWit/Taproot | Bitcoin XT/Bitcoin Cash |
Another intuitive way to interpret these is as follows:
The previous two successful consensus upgrades (SegWit and Taproot) both utilized soft forks, avoiding significant community splits. Thus, this article focuses on soft forks, which enable upgrades while maintaining compatibility with older software.
The typical workflow of a BIP proposal leading to a soft fork is illustrated below:
Source: https://river.com/learn/what-is-a-bitcoin-improvement-proposal-bip/
Soft forks often combine multiple BIPs into a single proposal. For example, Taproot incorporated three BIPs:
Timeline of the Taproot Upgrade
Source: Kraken Intelligence, GitHub, CoinDesk, https://www.argoblockchain.com/articles/bitcoin-taproot-upgrade-explained
Key milestones in Taproot soft fork:
It is important to note that this process is a retrospective summary based on historical observations, and in reality, there is no formalized consensus on this milestone.
Throughout the process, the Bitcoin Development Mailing List has played a pivotal role in consolidating consensus among various parties.
As mentioned at the beginning of the article, there are currently three main perspectives within the community regarding upgrades:
The author conducted an analysis of the pros and cons of upgrading versus not upgrading.
Consensus Change | Pros | Cons |
---|---|---|
Change | Technological Advancement, Enhanced Security, Expanded Use Cases | Risk of Forking, Increased Complexity |
Unchanged | Stability and Trust, Avoids Split Risks, Minimizes Attack Surface | Technological Stagnation, Lacks Flexibility for New Demands |
As a pragmatic developer in the Bitcoin ecosystem, the author believes that fully exploring Bitcoin's potential through cryptographic or engineering innovations within the existing protocol framework is indispensable. At the same time, from the perspectives of "sustainability" and "adaptability," it is advisable to implement continuous upgrades as needed, provided the impact and security risks are thoroughly evaluated.
In Bitcoin’s history, the Hong Kong Consensus (signed during the Bitcoin Roundtable in February 2016) identified three primary stakeholder groups:
As Bitcoin adoption has grown rapidly, the stakeholder landscape has evolved from this simple triad into a more fragmented and competitive environment. This is illustrated in the informative report from Analyzing Bitcoin Consensus: Risks in Protocol Upgrades.
Among these stakeholders, several key roles are worth highlighting:
Key Observations on Stakeholders:
OP_CAT
.Public data reveals multiple soft fork upgrades since Bitcoin’s inception.
Data Sources:
From the chart, 2 conclusions can be drawn:
Analyzing past soft forks and their associated BIPs, the following focus areas emerge:
Focus Area | Examples |
---|---|
Scalability | SegWit/Schnorr |
Privacy | Taproot/MAST/P2SH |
Programmability | CLTV/Tapscript |
Security | Disable Opcodes |
Based on the analysis above, a good upgrade proposal should:
The author has compiled most of the active proposals, assigned focus area tags to them, and categorized them into four quadrants to provide readers with a visual understanding.
Points to note regarding the classification:
From the chart above, the community appears to have reached some consensus on the problems upgrades should address, particularly in two areas:
The author believes that the Bitcoin community has fallen into a consensus maze regarding the next upgrade due to the following reasons:
This article introduced the fundamental concepts of Bitcoin upgrades, provided an in-depth analysis of historical upgrades, and reviewed active proposals for the next upgrade. The causes of the current "consensus puzzle" were also identified.
Key takeaways:
During the research, writing, and review process of this article, I received tremendous support, including from community members who, for various reasons, preferred not to be named. I extend my heartfelt gratitude to all of them.
Note: Given that some viewpoints in this article reflect personal preferences, the individuals listed below are NOT necessarily in full agreement with the content. This article does NOT intend to involve these generous community members in any political discourse.
Throughout the process, the author has identified many issues worthy of further exploration, such as solutions for certain functionalities, research on specific proposals, and data support for certain viewpoints. These topics will be elaborated upon in subsequent articles in the series.
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