Unlimited development team successfully deployed Xthin block (extremely thin block)

Chapter 0 Introduction

Currently, the transaction volume that a 1M block of Bitcoin can carry is very, very small, only 3 transactions per second. At present, the data transmission efficiency of Bitcoin is very low, so many developers believe that larger blocks are dangerous, which is also an important reason why Bitcoin Core dev (Bitcoin Core Development Group) refuses to expand the chain. But now the community has a solution to Bitcoin data transmission efficiency.

Chapter 1 Xthin (extremely thin block) and Compact block (compact block)

1M blocks have limited transaction volume, but they are safe for long-term use. Larger blocks have lower transmission efficiency between complete nodes, which will lead to the occurrence of orphan blocks, which is the bottleneck of on-chain expansion. This problem has led many experts in the community to believe that the network is unsafe if the block size is larger than 4M. In this context, some people in the community proposed to improve the block transmission mode to break through this bottleneck. They proposed the concept of Xthin (extremely thin blocks) to optimize the transmission efficiency of Bitcoin blocks between nodes. The main contributors to the Xhtin idea are: Andrew Clifford, Peter R.Rizun, @sickpig, Andrew Stone and Peter Tschipper.

Xthin (extremely thin blocks) increases the speed of block transmission between nodes by 5.6 times compared to the current block architecture. This will allow the Bitcoin network to easily broadcast blocks within 22M. Therefore, this concept has been embraced by the entire community, including Bitcoin Core, Bitcoin Unlimited and Bitcoin XT, which all have plans to deploy this protocol upgrade.

It is important to note that deploying the Xthin block does not require a fork, either a hard fork or a soft fork.

All development teams have thought of similar ideas, and gmaxwell also released an overview of similar ideas at the end of 2015.

Unlimited dev proposed BUIP 010 to deploy Xthin to Bitcoin Unlimited. BUIP 010 was released on January 10, 2016 and can be found on gitbhub. The link is as follows:

2016-1-10, xthin's BUIP, BUIP010 was created

https://bitco.in/forum/threads/buip010-passed-xtreme-thinblocks.774/

In response to the Xthin concept, the Bitcoin Core development team also proposed a concept called Compact Block, which is also used to optimize the transmission efficiency of Bitcoin blocks. In fact, it is a replica of Xthin and the two are exactly the same.

The Bitcoin Core development team proposed BIP 152 for Compact blocks, attempting to deploy Compact blocks to the Bitcoin Core wallet. BIP152 was created on github on April 27, 2016, the link is as follows:

016-4-27, compact block's BIP, BIP152 was created

https://github.com/bitcoin/bips/blob/master/bip-0152.mediawiki

Both parties have codes on Github because they are developing things with the same functions, and they both use an enumeration value (enum) with the same name, namely: MSG_CMPCT_BLOCK. If both are developed, and the Bitcoin Unlimited and Bitcoin Core clients run simultaneously in the Bitcoin network, there will be problems. This enum is the "secret code" for the client communication handshake. When the secret code matches, communication will begin according to the pre-agreed communication format. Bitcoin Unlimited used a "secret code" in advance, and the version released by Bitcoin Core used the same "secret code", but when the Core and Unlimited clients began to communicate, they found that there was actually a problem. So one party must make changes, and Bitcoin Core dev opened a new discussion group on Github for this issue. It was just opened the day before yesterday and has now been closed:

https://github.com/bitcoin/bitcoin/issues/8500

The title "MSG_CMPCT_BLOCK enum value is already in use" means that MSC... this enum value has already been used.

Regardless of the enum value discussed in this discussion group, I am concerned about the good news it brings us - Xhtin has been successfully deployed to Bitcoin Unlimited! Xhtin has been successfully deployed to Bitcoin Unlimited! Xhtin has been successfully deployed to Bitcoin Unlimited!

Good news should be told three times.

Chapter 2 Bitcoin Unlimited has successfully implemented Xthin blocks (extremely thin blocks)

The discussion group was initiated by a member of the Bitcoin Core development team. The topic of discussion was whether to rename an enumeration value in the Bitcoin core project to distinguish the two communication codes in compact block and Xthin Block.

The topic has obviously gone off topic, everyone is discussing why core dev didn't develop code to optimize block propagation before competitors (unlimited, XT and classic). Unlimited dev's priority in developing Xthin is embarrassing for core dev.

At the beginning of the discussion, we were told that Xthin has been successfully deployed on Bitcoin XT, Bitcoin Classic and Bitcoin Unlimited. The original text is as follows:

The existing type MSG_THINBLOCK is already in use and widely deployed: In Bitcoin XT, Bitcoin Classic and Bitcoin Unlimited.

The existing type "MSG_THINBLOCK" is already used and widely deployed in Bitcoin XT, Bitcoin Classic and Bitcoin Unlimited.

This tells us that Xthin has been successfully deployed. This is really good news, as Bitcoin chain expansion has a technical foundation.

Chapter 3 Bitcoin Development: A Major Victory in Decentralization

For a long time, there has been a rumor in the Chinese community that the Bitcoin Classic development team is not capable. Even under Gavin's leadership, many people think that they have not done anything serious, except to change the block size limit from "1M" to "2M". Gavin even wrote an article to explain that what Classic did was not as simple as changing a parameter.

The community, especially the Chinese community, has a worse impression of XT. Especially since Mike, an important code contributor, defected, everyone thinks that these people are good-for-nothings. Anyway, they think these people are far inferior to Core dev.

Unlimited dev also left a mediocre impression on everyone.

Chinese miners also frequently engage in high-level negotiations and cooperation with Core dev, but rarely communicate with Classic and Unlimited.

As for media opinions, Core dev completely occupied bitcoin talk, reddit/r/bitcoin and bitcoin.org. The voice of Core dev is the easiest to be heard by the community. You see, even the extremely important news that Xthin was successfully deployed, Unlimited dev did not widely spread the news to the Chinese community, but a core dev member told us in a github discussion group.

It can be said that the development of Bitcoin has been in a centralized state for a long time, and the evolution of the Bitcoin protocol is highly dependent on Bitcoin Core dev. This is very dangerous. In fact, we have also faced some embarrassing situations. The community users have highly unified their calls for the chain to be expanded to 2M, but Core dev ignored them and their attitude was extremely brutal.

But this time, with the successful deployment of Xthin, I saw for the first time that the Core dev members began to feel a sense of crisis. But the participants in this discussion group on GitHub include the famous @luke-jr and the leader of Core dev @gmaxwell.

While @luke-jr and @gmaxwell strongly denied that Unlimited dev's achievements put Core dev's development in a less competitive position, others in the discussion group thought they were somewhat embarrassed, with @zander saying:

@zander:I think if you ignore this valuable feedback on your competing design, while there is a clear demonstration that your not-yet-released software can't interoperate with something that has been on the market for 6 months, you are creating a disruption to the Bitcoin ecosystem and on top of that you should be ashamed of yourselves.

I think if you ignore this valuable feedback from competing designs, the same design has been successfully running in the market for 6 months, and you haven't released any improvements, you are causing trouble for the Bitcoin ecosystem, and most importantly you should be ashamed of yourself.

However, @gmaxwell refused to admit that Core dev was lagging behind, and brazenly said that the overlapping functions of Xthin and Compact block did not matter, and accused this discussion group of being wrong and should be closed immediately.

@gmaxwell: I don't see anything wrong here. I think the issue was incorrectly opened.

I don't think there is anything wrong here, I think it's a mistake to open this discussion group.

But @zander once again said that @gmaxwell should respect the market and pay attention to the fact that their development projects have lagged behind their competitors because they are too lazy:

@zander I repeat myself, you should be ashamed of yourselves.

Having a bigger market share doesn't give you the right to tell others to recall their products already 6 months on the market because you are too lazy to do fix yours before your release.

I repeat, you (referring to gmaxwell) should be ashamed of yourself.

In a competitive market, even if you have a larger market share, you have no power to make your competitors recall a product they released 6 months ago just because you were too lazy and let them get ahead.

Core dev has indeed proved their ability to the community for a long time and won a monopoly market share. However, this has led to Core dev's neglect of users. They are highly unified externally and use means of restricting freedom of speech to spread their own policies and suppress the ideas of competitive development groups. This is not a very good thing for Bitcoin, which aims at decentralization. Now we are fortunate to see that the success of Unlimited has attracted the attention of Core dev, which is a manifestation of decentralized development.

Chapter 4 Core dev will have to pay more attention to user needs

The successful deployment of Xthin by Bitcoin Unlimited dev will inevitably bring market share, because Xthin is great for full nodes, and the bandwidth share has dropped all at once. This is a real benefit.

In the past, many users ran Bitcoin Classic nodes just to express their firm attitude towards capacity expansion, not because its performance was better than Bitcoin Core. But with the performance support of Xthin, this situation will be broken. In addition to expressing attitudes, there is also interest support. Especially in China, where there are restrictions on GFW and export bandwidth is limited, people are more inclined to run Bitcoin Unlimited.

I am not saying that the Bitcoin protocol will switch from Bitcoin Core to Unlimited, which requires a hard fork and 75% of the network's computing power. I am just saying that users can use Bitcoin Unlimited, Classic, or even XT wallets that have deployed Xthin (extremely thin blocks) to reduce the bandwidth usage of running a full node. Anyway, I will install a Bitcoin Unlimited wallet to try.

Bitcoin Core dev often ignored user needs, especially the need to increase block size, because users really did not have a clear better option than Bitcoin Core for a long time. Now there is one. Not only does the software version have an advantage, but the development team has also proven its strength.

When the real market demand shifted to the Xthin function, Bitcoin Core failed to develop the Compact Block with the same function in time, and was unwilling to lower its head to integrate Xthin, and continued to insist on BIP152 (which is actually no different from pirated Xthin), which inevitably failed to keep up with market demand in terms of time. The developers of Core dev will inevitably be under market pressure. This will help them listen more to user needs, such as block expansion.

Chapter 5 Conclusion

During the high school entrance exam, I was not very good at sprinting in the physical education test. The teacher asked me to run with the best sprinter students, which would help me get better results. It really worked, the effect was very obvious.

Market competition is a good thing. The stronger the competitors, the more motivated you will be to make progress. Bitcoin development has been centralized for a long time. No competition is not a good thing. Whether it is Bitcoin Core, Unlimited, Classic, or XT, I wish them all the best. Bitcoin, this great experiment, will truly change the world.