Big ideas in BCH

The vision of Bitcoin Cash is to become peer-to-peer electronic cash for the world, this huge goal requires new innovative ideas and technologies to further extend the solid Bitcoin foundation. In this post we'll go over prominent big ideas.

From a loose to strict roadmap and back

In the talk "Back to the Basics" from June 30th 2017 where Bitcoin Cash was effectively announced there was a slide "in the pipe" which laid out a loose roadmap.

In the article "The Bitcoin Cash Roadmap" from September 2017, Chris Pacia listed six items which seemed to have rough high level consensus for an ambitious, long term Bitcoin Cash roadmap which apart from "a new difficulty adjustment algorithm" includes the same things as the slide above but with extra explanation for each item. This rough outline roadmap was introduced well before "The Bitcoin ABC Vision" subtitled "Proposed Technical Roadmap for Bitcoin Cash", which was released Aug 24th 2018. In some regards the old rough outline gets the point way better across than what ABC laid forward. The latter has little extra information on each item displayed and is maybe too technical with regards to scaling on not big picture enough with regards to extensibility but I digress, as ABC split from BCH so has their roadmap. But with ABC leaving and BCHN being created, the big ideas didn't suddenly change. In the BCHN flipstarter under "prime candidates for future independently crowd-funded features" there is UTXO/UtreeXO commitments, "Evaluate Storm or Avalanche as pre-consensus options" and "Better block propagation with compatible Xthinner and/or Graphene" among other things. So while there is no exact roadmap as ABC laid forward it's certainly possible to gauge a general sentiment for a broad consensus as Pacia did.

Lots of discussion happened meanwhile

In 2018 the ideas of pre-consensus and tokens were actively debated. Bitcoin ABC picked Avalanche as their preferred method for pre-consensus to achieve instant transactions, moving on from the weak block/NG ideas listed on the initial slide. "Storm", introduced in Aug 2019, is a new iteration on the weak block idea. Currently both ideas are considered to require more research as articulated by BCHN in their flipstarter. Tokens were also a an important point of discussion with many competing tokenproposals, eventually SLP tokens were the ones to gain traction.

What's done and what worked well

Currently on Bitcoin Cash Malleability has been fixed and a new Difficulty Adjustment Algorithm (DAA) called "aserti3-2d" was introduced last year. The ordering of transactions was also changed to "CTOR" the focus of this change was long term scaling by enabling sharding. The change to CTOR has been criticized for being premature and posing a considerable cost to the network. Protocol upgrades for better scalability have only a potential payoff when BCH is already wildly successful but pose a big (opportunity)cost in the present regardless that's why ideas like merklix trees or the UTXO/UtreeXO commitment proposals are currently not on high priority. In contrast Extensibility upgrades like re-enabling old opcodes, increasing the op_return size and introducing opcode checkdatasig have instantly enabled new usecases and projects without having the same disruptive drawbacks.

What's next

Because node teams agreed to add no new features in the May hardfork of this year teams have been working on non consensus changes such as Double Spend Proofs (DSPs) and unconfirmed transaction chains. For what will be included the upgrade after it's a very good sign to see protocol developers working on new transaction-introspection opcodes, higher opcode limits, multiplication opcodes and larger integer numbers, changes which together would really make a difference for smart contract developers & projects on BCH. These are things the people behind General Protocols which designed Anyhedge have asked for to be able to develop their more advanced smart contract for BCH. These scripting changes will presumably be bundled in a "scripting upgrade" in May 2022 which would be the next upgrade with the relaxation from a six month hardfork schedule.

Miner validated tokens

Recently with the draft proposal "Cashtokens" for minervalidated tokens on BCH and the departure of ABC, miner validated tokens are actively being discussed again (see bitcoincashresearch.org). The cashtokens proposal prides itself in being a minimally intrusive change and as a more general extension of the BCH capabilities by being the counterpart of 'convenants' which are forward validating by introducing backward validation. The Group proposal for minervalidated tokens, which was first introduced in Nov 2017 is another proposal for miner validated coins on BCH. As Jason Dreyzehner, the author of Cashtokens, has pointed out the two are not mutually exclusive. The 'Group' has faced criticisms for being too intrusive but promises to "make tokens first class citizens on BCH." It will be interesting to follow how the proposals evolve under technical scrutiny and if either or both find widespread support. The promises to enable uniswap-style DEXes, onchain ICOs , prediction markets and "Transferable Synthetic Assets" are too great to just overlook. The ideas for miner validated tokens, while never on the roadmap, is potentially one of the highest impact ideas in BCH. It is proof of an innovative culture and thriving intellectual space.