Core developer: Block expansion is no longer a key issue for Bitcoin development

Everyone is focusing on the issue of blockchain expansion, but there is actually more important things.

The remarks, made by Cornell University professor Emin Gün Sirer on the second day of the Scaling Bitcoin conference, were perhaps the most important takeaways from this year’s gathering of digital currency network developers.

Although Roger Ver deliberately chose to hold a similar discussion on the same day (mainly discussing proposals that were not adopted by Scaling Bitcoin), this year's Scaling Bitcoin still proved one thing from the side - for most developers, "block capacity" is no longer an important factor in improving network performance.

The two-day meeting spent a lot of time discussing the issue of "trade-offs", that is, what trade-offs should be made when the basic elements and complex interaction methods of Bitcoin change.

Bitcoin Core developer Eric Lomborozo told CoinDesk:

All engineering designs involve trade-offs. We are actively exploring various development possibilities to make the most appropriate trade-offs.

However, Lombrozo admitted that the block capacity issue (whether the hard-coded limit on the number of transactions that Bitcoin can process should be changed) is still a “cultural phenomenon” (cultural phenomenon here means the inevitable way things develop) and the direction of the technical community, after all, the current market is dominated by blockchain solutions.

The second day of the meeting explained in depth the reason for this shift in focus. Christopher Allen, chief architect of Blockstream, said that the social consensus recognized by developers meant that block expansion would no longer be a big problem.

I think since the last meeting when SegWit was proposed, everything has been very clear, and now it’s just a matter of reaching a consensus. In fact, the technical community has been one step ahead.

Blockstream core engineer Greg Sanders emphasized that the focus of his speech was to hope that the community could gain some inspiration from the development of Segregated Witness, which is implemented as a soft fork and will change the way transactions are stored on the network.

Stop talking about scaling. We should start talking about quantity, i.e. transaction volume, number of blocks, and the impact of external factors on the Bitcoin system. We should start talking about transaction processing efficiency. We are able to store more data in a smaller space, so we should start thinking about the above issues.

Blockstream’s Jorge Timón even went so far as to say that block capacity is “not an interesting topic” at all.

“Social bifurcation”

Although what Timón said does represent the majority of people, there is still a small number of people who oppose it, and the term "social bifurcation" can be used to describe this development.

Roger Ver, a well-known supporter of larger blocks, hosted a "free speech party" on the evening of the Scaling Bitcoin conference, which attracted about 20 participants. The party mainly discussed some proposals that were rejected by Scaling Bitcoin, and also explained why increasing the block size can accommodate more user needs.

The party focused on极瘦区块（Xthin blocks） and other scaling proposals from researchers such as Bitcoin Unlimited, which is said to not slow down the propagation of blocks between nodes and miners.

In addition, they pointed out the reasons why Scaling Bitcoin rejected some proposals and the fear of other digital currencies replacing Bitcoin in the market. In addition, participants criticized the speech of this conference for having no real basis, because "vaporware" (products that are promoted before they are completed and may never come into being) such as Lightning Network is still regarded as the best expansion solution.

Jerry Chan of Bitcoin Unlimited believes that the reason Scaling Bitcoin rejected his proposal was to “avoid endless debate at all costs.”

I think it's very effective that they're blocking some proposals because that directly addresses all the problems that existed in the past.

Perhaps most notably, the “protest” also attracted several mining company representatives, including Jihan Wu of Bitmain and Haipo Yang of ViaBTC.

Incremental change

The second day of the Scaling Bitcoin conference also highlighted proposals for smaller changes to the network, which can sometimes have more complex effects on Bitcoin.

For example, Blockstream’s Peter Wiulle compared Schnorr签名to the Elliptic Curve Digital Signature Algorithm (ECDSA) in protecting user funds. His presentation was intended to highlight that even minor changes require a lot of preparation.

Schnorr signatures are not a standard. ECDSA is a standard document that details all the math. Schnorr represents the general idea.

Wiulle said that isolated verification can enable Schnorr signatures. When there are multiple transaction inputs, only one signature is needed, and only this signature can send transactions in the network. However, he pointed out that the structure of Bitcoin addresses will cause problems for Schnorr signatures, that is, new potential attack vectors, so there is still a lot of work to be done on this issue.

Another talk was about the performance of PoW blockchains, comparing the block propagation speed of the Bitcoin network with other blockchain networks.

Arthur Gervaise, a representative from ETH Zurich, presented the results of their experiment, which successfully 10分钟减少到1分钟, achieving a processing speed of每秒钟60笔交易.

The above speeches do not mean that this conference is not about the main issues. Prominent developers such as Peter Todd and David Vorick have also proposed some plans to reshape the Bitcoin network.

The most noteworthy of these is Todd’s proposal to achieve expansion through client verification. First, he asked whether miners need to verify transactions. He believes that redefining the relationship between miners and nodes is more conducive to achieving scalability.

It can be said that miners verifying transactions is the best option. This approach does bring some interesting social effects. I can create a rule that allows Litecoin (LTC) and Bitcoin to coexist in the same system.

Academic Sharing

However, Bitcoin's adherence to some basic principles seems to have constrained some experts, who believe that it will be difficult to solve some more important problems in this way.

Sirer mentioned in his speech that he intends to update his “比特币金库”（Bitcoin Vault） proposal. He believes that some "agreed matters" should be added to transactions, which can effectively prevent the risk of funds being stolen. However, during the Q&A session, the audience raised many pointed questions.

Sirer said his proposal did face opposition. Some people believe that this approach would jeopardize可互换性（fungibility） of Bitcoin or any property that can be exchanged for Bitcoin. However, he still believes that this seemingly imperfect solution has its own advantages.

Ultimately, fungibility will not be protected by in-protocol mechanisms. Only a social contract can ensure that fungibility is necessary.

Bryan Ford of the Swiss Federal Institute of Technology in Lausanne (EPFL) said he would like to see more “significant improvements”.

Ford calls himself an “outsider” and believes that the community’s narrow view of Bitcoin development can easily influence external investment.

Ford’s comments point to the fragmentation of the bitcoin community, which has been fueled by a rush to resolve scaling issues.

However, Ford believes that based on the current situation, there is still some progress.

The community’s focus is becoming more diverse and not just limited to block capacity issues, which is a good thing.