nChain Is Strongly Against Canonical Transaction Ordering (CTOR) Proposal

Does nChain Oppose Canonical Transaction Ordering (CTOR)?

Recently, there has been a lot of discussion in the crypto world regarding the benefits and risks of Canonical Transaction Ordering proposal (CTOR). While many are quite supportive of the proposal, believing that it will be a good thing in the long run, there are also those who are strongly against it.

Canonical Transaction Ordering proposal

To put it simply, the CTOR is a proposal to change the ordering of transactions within Bitcoin Cash's blocks. BCH is currently using TTOR, or Topological Transaction Ordering, which has served it well so far. However, as part of the constant development and change, there is a belief shared by many, including Bitcoin ABC, that a change is due.

The changes that the implementation of CTOR would bring are many, and most of them seem to be quite positive. For example, Bitcoin ABC claims that CTOR would be much simpler in terms of implementation than TTOR. Not only that, but CTOR has a huge potential to improve the performance of BCH since a large majority of the block template creation time is wasted because of ordering requirements.

Apart from these, there are numerous other benefits that would come with CTOR implementation, such as better parallelization, improved security, easier transmission of blocks, and alike. However, while all of this sounds pretty good so far, not everyone agrees that CTOR is the right way to go.

nChain Against CTOR

In its own evaluation titled “Canonical Transaction Ordering for Bitcoin: A Critical Evaluation”, the nChain team argues strongly against CTOR. They claim that the proposal promises many benefits, some of which we have listed earlier, but that there is no sufficient demonstration that can confirm that the benefits are real.

Not only that, but nChain also claims that the risks of replacing TTOR with CTOR would be greater than the benefits anyway. Because of this, they argue that the CTOR implementation is to be avoided at all costs.

As far as the Bitcoin community is concerned, there are those who agree with nChain, but also those who do not. nChain argues that the CTOR is facing a significant opposition from the community, which by itself poses a question whether it should be implemented or not.

As for the risks, nChain is fearing numerous bugs that might appear due to the change, as well as edge cases that may not appear for all future users. They also noted that Bitcoin Unlimited members voted mostly against CTOR, with 22 votes being against it, and only 5 in favor of it, while 3 abstained from voting.

In the end, nChain claims that a consensus change implementation is risky as it is. However, implementation of one when the opinions are as divided as they are now is even worse. Because of that, they believe that the risks are high enough to outweigh any potential rewards or benefits of the proposal.