Why Bitcoin Core should stay the main Bitcoin implementation?

[Dogedegen]

Bitcoin has core principles of decentralization, immutability, and security and these currently depend largely on the Bitcoin Core implementation. As Bitcoin continues to grow and evolve the question sometimes is asked: Should Bitcoin Core remain the primary implementation? I tried to provide a overview of the benefits and risks of keeping Bitcoin Core in the same position as it has been, and mentioned some other perspectives of the challenges too. I tried to keep the points short and be precise. With the OP_RETURN drama and other things happening, many attacks on Bitcoin Core are being done but they are just evil and causing harm. I think more positive threads would be a good counter move, I hope I didn't do too badly.

1. Security
The security Bitcoin is one of its most valuable features, and Bitcoin Core is being constantly vetted by many different contributors, engineers, outside observers, auditors and others. Over the years the code has undergone extensive scrutiny by a large number of global individuals, we do not even know the exact number. It is because of this and its thorough review process for adding code and making releases that i has become the more secure implementation of Bitcoin. While other implementation might have some of their own merits and issues, they do not have the same level of security or time that they have been field-tested. The software is very predictable as we have observed how it manages to deal with difficult situations such as mempool pressures and reorganizations. The benefit of keeping Bitcoin Core in terms of security is very high, it is very unlikely to have critical flaws even if it still does happen sometimes even if rarely. It would be very hard for another implementation to replicate the level of security and battle-tested level of Bitcoin Core.

2. Consensus
Bitcoin depends on consensus. If we have many competing implementations then there would be a much bigger risk of network splits of different risk. This does not mean that a network split would automatically happen, but the risk is significantly increased depending on the number of competing implementations and their used versions. Right now Bitcoin Core is the standard for Bitcoin's consensus rules, and if we had different implementation there could be more orphan blocks leading to losses to miners or even a complete split of the network. If there is a hard fork or several forks that are caused by multiple competing implementations this would harm Bitcoin's reputation, integrity and security! It is easier to keep the network unified if all the participants are running Bitcoin Core as only compatibility between the used versions would need to be assured compared to between versions and across different implementations.

3. Stability vs. Speed
Bitcoin Core is slow to adopt changes. With more critical or dangerous the changes they are even slower. While some shitcoin proponents see this as a disadvantage as they do not understand the value proposition of a decentralized network like Bitcoin, this is one of the biggest strengths of Bitcoin Core. One could say that this is related to the first point, but speed and security do not have to be related. There are very slow moving projects that have been very insecure, and they are some faster projects that have been pretty secure in relative terms. Keeping Bitcoin Core as the main implementation gives us this slow and deliberate process where Bitcoin's integrity is in the first place, and new features come second. Bitcoin Core makes sure that risky changes that could damage the network are never rushed. We can't really say the same for other projects and teams, if we look at shitcoins they take the opposite approach and this sometimes leads to complete network halts, complete smart contract hacks and more.

4. The Network Effect of Trust
Basically it was always true in Bitcoin's history that Bitcoin Core has the largest adoption among all groups, miners, developers, and users. Because of this there is a very strong network effect and the trust in Bitcoin Core has been built up over more than a decade of reliable operation. Even if we only had 2 competing implementations it would risk this trust and create confusion. I think it would be very hard for a new implementation to convince the majority among all groups of the ecosystem to adopt it, except maybe in some very extraordinary or unlikely circumstances. This is why even such an attempt would always lead to fragmentation to the network and more difficulties for everyone involved, even now we have some version fragmentation of Bitcoin Core.

5. Natural Decentralization of Development
The development in Bitcoin Core is open source and it is decentralized, but the special part of this is that it became this way naturally. It evolved through time, we could say that at the beginning it was centralized and satoshi was in control but after some a short period of time this changed. The project continued to involve and now nobody really has any power over it or any control, it is really hard to try to recreate this with purpose. This is one of the main reasons why Bitcoin is so much more resilient compared to shitcoins. A single party or a concentrated effort to control the development of Bitcoin would not work. An alternative implementation is probably always going to be more centralized than Bitcoin Core, and at times it could be dangerous like Bitcoin Knots which is fully under control by a single person. In theory Bitcoin could survive even if its main implementation got centralized because the network participants would refuse to update, but this would cause a lot of chaos and transitioning again to another decentralized implementation would be very hard.

6. Fragmentation
This has already been mentioned a bit as a consequence of some other points, but I think this risk deserves its own point. Even if it is not very clear how exactly an attacker would approach to attack Bitcoin from the development side since nobody is in control and the things are set up in a way that everyone can review everyone else, most of the things that we have right now are clear. We have the development mailing list, the BIP process, the main implementation Bitcoin Core, some communication channels also IRC and even Discord I think. So if one wants to improve Bitcoin in certain ways or contribute something, it is a bit more clear how to do it and how consensus on changes is done. But just think how hard this would be if we had 5 different implementations and each had its own thing going on. Some could have more private communications than others. How would one do a BIP if each implementation has its own thing? I think here is a big risk besides consensus splitting to split into social or political factions, and then instead of changes being analyzed objectively for benefits and risks they could be pushed for or rejected for political reasons. Some great BIP could be rejected because someone wrote it who people from other implementations do not like. There would be more costs in everything, in reading proposals, in communicating, trying to make sure they work between implementations. A lot of work to reduce the big risk to Bitcoin's integrity but for what benefit?

7. Power Imbalance
This could be the first big risk of keeping Bitcoin Core in this list. Bitcoin works for many reasons, but one of them is a good balance of powers between developers, miners, and nodes or users. It is important that this balance is kept in check, because if either miners or developers gain supreme power we would lose what makes Bitcoin so good. I personally think that the ultimate power lies with the users and it should be this way, but this comes with some considerations. Very few users are able to consider technical topics and think about the development future of Bitcoin. Very few users could run large mining operations. Everyone has a role to play, so even if users should maybe have some more power than the other 2 groups, each one needs the other 2. If Bitcoin Core is never challenged, questioned, criticized, then there is a risk of creating an imbalance of power where those that contribute to Bitcoin Core just do whatever they want even if the changes are not consensus related. I think good communication between all 3 groups is important.

8. Hijacking Bitcoin with a Switch
This maybe could be considered more of an attack, but it could also be seen as a risk of changing Bitcoin Core. We need to think how switching to a new main implementation would even look like, because it sounds very simple like changing your shirt but it is extremely complicated. To which implementation should we switch? Who is to control this implementation? How can we trust it? Even if the code is open source that does not mean that over time things can't be sneaked into it by pretending that some changes do not have bugs, people who look from outside may not notice them. I've talked a bit with other users about the potential for large entities and institutions to co-opt Bitcoin, well this is probably one of the best way to do it. When these is panic about some issues, quantum computers, satoshi coins, something, try to attack Bitcoin Core as much as possible and introduce a new implementation where you have control. We know well that if people have very deep pockets to spread propaganda and sway users, that they can sell lies about decentralization and benefits to the public. We have seen this with shitcoins, there are many users who believe that shitcoins which are completely controlled by a company or foundation are as decentralized as Bitcoin.

9. Integrity loss through failure to Switch
This point is the opposite case of point 8. Let's imagine that in some way Bitcoin Core is completely compromised or going against the wishes of everyone else in the network. Let's not dwell in details how this could happen, there are many scenarios that we could speculate on with different probabilities even if they are low. This point is more about, what do we do if we find ourselves in a highly improbable scenario like that? There are good benefits of keeping a single implementation over time as I have described, and these benefits probably outweigh the opposite case. But we also have no experience at all switching to another implementation. If the main implementation is compromised and we fail to find consensus on what to switch to, or who to switch to, then we risk losing the integrity of Bitcoin this way. I think a fallback solution to this would be to just stay on the last known good version of Bitcoin Core. But this can only work temporarily, we can't run this version forever so even in this case a solution must be found.


Conclusion
Bitcoin Core is not perfect but nothing is, and over the years they have made some choices that not everyone agrees with but we are still here. It is the implementation with the most users, and is the most secure, stable and trusted one. Some other implementations exist, but they are limited in support, and come with huge new risks that relate to security and centralization. These risks outweigh the benefits in a environment where multiple implementations are competing. Trying to replace Bitcoin Core even if there was a very good reason to do so would introduce new attack vectors that could completely undermine the entire Bitcoin network and create unseen amounts of chaos.

Bitcoin Core is the backbone of the whole network and with it Bitcoin remains secure, mostly unified and true to its original vision. I don't think that we will see any changes in this aspect of Bitcoin in the foreseeable future.

[MusaMohamed]

Bitcoin Core is not perfect but nothing is, and over the years they have made some choices that not everyone agrees with but we are still here. It is the implementation with the most users, and is the most secure, stable and trusted one. Some other implementations exist, but they are limited in support, and come with huge new risks that relate to security and centralization. These risks outweigh the benefits in a environment where multiple implementations are competing. Trying to replace Bitcoin Core even if there was a very good reason to do so would introduce new attack vectors that could completely undermine the entire Bitcoin network and create unseen amounts of chaos.

Bitcoin project is a decentralized one that opens space of developments, contributions from everyone. Bitcoin blockchain is decentralized and Bitcoin community are decentralized too so Bitcoin Core is only one of many choices. Whether Bitcoin Core remains its leading role in this industry will depend on itself, and it's not right to say we should keep using Bitcoin Core just because of its wallet software name.

Its quality since its beginning till now is importand decisive reason why most Bitcoin users are prefer Bitcoin Core if they manage to use it, but it is not like a forever shield for Bitcoin Core. If it is like this, it will restrict developments and growths of other Bitcoin wallet softwares, that is not good for Bitcoin community.

[NotATether]

There is simply no other reference client with the same degree of maintenance and code review. In fact, it is quite telling that the only two types of nodes people are running are Core and Knots (which is just Core with a few patches on top of it). There has never truly been a popular reference client with a different architecture.

[Alvin_talk]

Nice thread!!
Although, I think  for bitcoin core to become a dominant implementation is not the goal here, the goal should be to work with the implementation that protects Bitcoin's properties the most and Bitcoin core is no doubt the best at this.

1. Security
The security Bitcoin is one of its most valuable features, and Bitcoin Core is being constantly vetted by many different contributors, engineers, outside observers, auditors and others. Over the years the code has undergone extensive scrutiny by a large number of global individuals, we do not even know the exact number. It is because of this and its thorough review process for adding code and making releases that i has become the more secure implementation of Bitcoin.

To add to what you have said so far, I will say core's security is not only about review and time, I think its predictability has also played a major role (i.e We all know how it can behave under stress, how it handles mempool related pressures, reorg, etc). This operational knowledge is largely underrated IMO. Come to think of it, even if a technically neater version is introduced it will be risky because node operators, miners and users may not understand its failure modes yet.

2. Consensus
Bitcoin depends on consensus. If we have many competing implementations then there would be a much bigger risk of network splits of different risk.

May I add that multiple implementation do not automatically result to a split rather, it is when there are inconsistencies in the interpretation of consensus rules that results to split. Theoretically speaking, we could have multiple implementations so long as they are bit to bit compatible on behaviour, not so? However, this may be different in reality if we consider historical quirks, soft-fork edge cases that are present in the consensus rules and replicating this is extremely difficult.
Let's make this clear, One of the reason bitcoin is surviving is because of its boring nature.

[Dogedegen]

There is simply no other reference client with the same degree of maintenance and code review. In fact, it is quite telling that the only two types of nodes people are running are Core and Knots (which is just Core with a few patches on top of it). There has never truly been a popular reference client with a different architecture.

That is true and I tried to say it in some points. If someone wanted to replicate that with intent it would be very hard, cost a lot and it may not even get close to what Core is. Bitcoin Core is very important to Bitcoin!

Nice thread!!
Although, I think  for bitcoin core to become a dominant implementation is not the goal here, the goal should be to work with the implementation that protects Bitcoin's properties the most and Bitcoin core is no doubt the best at this.

Thank you. You are right about the goal, maybe we could say that same thing just differently. Bitcoin Core became the dominant implementation because it protects Bitcoin's properties the most!

1. Security
The security Bitcoin is one of its most valuable features, and Bitcoin Core is being constantly vetted by many different contributors, engineers, outside observers, auditors and others. Over the years the code has undergone extensive scrutiny by a large number of global individuals, we do not even know the exact number. It is because of this and its thorough review process for adding code and making releases that i has become the more secure implementation of Bitcoin.

To add to what you have said so far, I will say core's security is not only about review and time, I think its predictability has also played a major role (i.e We all know how it can behave under stress, how it handles mempool related pressures, reorg, etc). This operational knowledge is largely underrated IMO. Come to think of it, even if a technically neater version is introduced it will be risky because node operators, miners and users may not understand its failure modes yet.

Maybe I should have been more explicit or extended that point, but I mention that no other implementation has the same level of security or time that they have been field-tested. Some people may see time too simply and assume if 2 implementations have been released 10 years ago that they have the same amount of time in field-testing, but I don't agree that it works this way. What has been more time tested an implementation ran by 1000 users over 5 years or an implementation ran by 10 users over 10 years? I think these things should be cumulative otherwise they don't show the full store.

2. Consensus
Bitcoin depends on consensus. If we have many competing implementations then there would be a much bigger risk of network splits of different risk.

May I add that multiple implementation do not automatically result to a split rather, it is when there are inconsistencies in the interpretation of consensus rules that results to split. Theoretically speaking, we could have multiple implementations so long as they are bit to bit compatible on behaviour, not so? However, this may be different in reality if we consider historical quirks, soft-fork edge cases that are present in the consensus rules and replicating this is extremely difficult.
Let's make this clear, One of the reason bitcoin is surviving is because of its boring nature.

You may, but that is not what I have said here. I said that there would be a much bigger risk, this does not mean that it would automatically happen. Strictly speaking, even having 2 different versions of the same implementation increases the risk of a split. This is why Bitcoin Core works so hard to ensure backwards compatibility with changes that are more risky, rolling them out gradually and other stuff that they do for that. So if you have different implementations each with its own different versions running on the network, then the risk of a split here in huge compared to the case when you have 1 implementation of a few versions or even bigger when we talk about only 1 implementation and 1 version. I will elaborate it a bit more in the points.