Bitcoin Cash's vision is to become the world's peer-to-peer electronic cash. Achieving this ambitious goal would take new creative concepts and technology to build on the strong Bitcoin base. In this article, we'll discuss some of the most significant major concepts.
In the June 30th, 2017 talk "Back to the Basics," during which Bitcoin Cash was effectively announced, there was a slide "in the pipe" that detailed a loose roadmap.
Chris Pacia's September 2017 article "The Bitcoin Cash Roadmap" listed six items that appeared to have broad consensus for an ambitious, long-term Bitcoin Cash roadmap that, aside from "a new difficulty adjustment algorithm," includes the same items as the slide above but with additional explanation for each item. This rough outline roadmap was introduced well in advance of the August 24th release of "The Bitcoin ABC Vision," subtitled "Proposed Technical Roadmap for Bitcoin Cash." In some ways, the old rough outline conveys the message much more effectively than ABC's presentation. The latter provides little additional information about each item displayed and may be too technical in terms of scaling and not broad enough in terms of extensibility, but I digress; as ABC separated from BCH, their roadmap also changed. However, with the demise of ABC and the establishment of BCHN, the fundamental ideas did not change. UTXO/UtreeXO commitments, "Evaluate Storm or Avalanche as pre-consensus options," and "Better block propagation with compatible Xthinner and Graphene" are all listed in the BCHN flipstarter under "prime candidates for future independently crowd-funded features." Thus, while there is no precise roadmap as ABC suggested, it is certainly possible to gauge general sentiment in order to arrive at a broad consensus, as Pacia did.
Meanwhile, a great deal of debate occurred.
The concepts of pre-consensus and tokens were hotly debated in 2018. Bitcoin ABC chose Avalanche as their preferred method for achieving pre-consensus and instant transactions, abandoning the weak block/NG ideas presented on the initial slide. "Storm," which was introduced in August 2019, is a new take on the weak block concept. Both concepts are currently considered to be in need of additional research, as articulated by BCHN in their Kickstarter. Tokens were also a hot topic of debate, with several competing token proposals; finally, SLP tokens gained traction.
What has been accomplished and what has proven effective.
Malleability has been fixed on Bitcoin Cash, and a new Difficulty Adjustment Algorithm (DAA) called "aserti3-2d" was implemented last year. Additionally, the transaction order was changed to "CTOR" to allow long-term scaling through sharding. The switch to CTOR has been criticized as premature and as imposing a significant expense on the network. Upgrades to the protocol for scalability may have a payoff when BCH is already extremely efficient. Still, they impose a significant (opportunity) cost in the present regardless of why ideas like merklix trees or the UTXO/UtreeXO commitment proposals are not currently a high priority. In comparison, extensibility enhancements such as re-enabling legacy opcodes, increasing the op return size, and implementing opcode checkdatasig immediately allowed new use-cases and projects without the same disruptive side effects.
What comes next?
Since node teams decided not to implement any new features during this year's Can hard fork, teams have been working on non-consensus improvements such as Double Spend Proofs (DSPs) and unconfirmed transaction chains. For what will be included in the subsequent update, it's a very positive sign to see protocol developers working on new transaction-introspection opcodes, increased opcode thresholds, multiplication opcodes, and larger integer numbers all of which will make a significant difference for smart contract developers and BCH ventures. These are the features that the creators of General Protocols, which created Anyhedge, have requested to build a more sophisticated smart contract for BCH. These scripting updates are likely to be included in a "scripting refresh" in May 2022, the next upgrade after the six-month hard fork timetable is relaxed.
Tokens that a miner has validated.
Recently, with the publication of the draught proposal "Cashtokens" for miner-validated tokens on BCH and the demise of ABC, miner-validated tokens have resurfaced as a topic of discussion (see bitcoincashresearch.org). The cash tokens plan prides itself on being a minimally invasive reform and a more general extension of the BCH capabilities by serving as the counterpart to 'covenants,' which are forward validating by the addition of backward validation. Another proposal for miner-validated coins on BCH is the Group proposal for miner-validated tokens, which was launched in November 2017. As Cashtokens author Jason Dreyzehner points out, the two are not mutually exclusive. The 'Gang' has been chastised for being too controlling, but it promises to "make tokens first-class citizens on BCH."It will be fascinating to see how the ideas develop when subjected to technical review and whether one or both gain widespread support. The promises of enabling uniswap-style DEXes, on-chain initial coin offerings (ICOs), prediction markets, and "Transferable Synthetic Assets" are just too compelling to ignore. While miner validated tokens were never on the road map, they can be one of the most impactful ideas in BCH. It demonstrates a creative society and a vibrant intellectual community.