Bitcoin Cash ABC vs. BCHSV: The Hard Fork and The Hash War

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In the ever-evolving world of cryptocurrencies, few events have sparked as much controversy and technical drama as the 2018 split within the Bitcoin Cash (BCH) community. What began as a philosophical disagreement over the future direction of the blockchain quickly escalated into a full-blown hash war between two competing factions: Bitcoin Cash ABC (BCHABC) and Bitcoin SV (BCHSV).

For a brief period, "Bitcoin Cash ABC" was more than just a software client—it became a symbol of one vision for decentralized scalability. However, by November 23, 2018, the dust had begun to settle, and Bitcoin Cash ABC emerged not as a separate entity, but as the de facto continuation of the original Bitcoin Cash chain.

But how did we get here? And what were the core differences that drove such a bitter divide?

Understanding Bitcoin Cash: A Brief Overview

Bitcoin Cash (BCH) was born on August 1, 2017, following a hard fork from the original Bitcoin blockchain. The split stemmed from an ongoing debate about how best to scale Bitcoin’s network. While the Bitcoin Core developers favored off-chain solutions like the Lightning Network, proponents of Bitcoin Cash believed in increasing the block size to allow for more on-chain transactions.

These supporters argue that larger blocks enable faster, cheaper transactions—making BCH a more viable peer-to-peer electronic cash system, in line with Satoshi Nakamoto’s original whitepaper vision.

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One of the earliest implementations of Bitcoin Cash was Bitcoin Cash ABC, where “ABC” stands for Adjustable Blocksize Cap. Unlike fixed limits, this model allowed users and miners to dynamically choose their preferred block size, promoting flexibility and decentralization. It gained strong backing from key figures like Roger Ver, CEO of Bitcoin.com, and Jihan Wu, co-founder of Bitmain—one of the largest mining hardware manufacturers.

The Road to the 2018 Hard Fork

On November 15, 2018, another scheduled upgrade triggered deep divisions within the BCH ecosystem. This time, two rival camps emerged with fundamentally different visions:

Bitcoin Cash ABC: Innovation Through Regular Upgrades

The Bitcoin ABC team advocated for continuous improvement through biannual hard forks. Their proposed changes included:

This approach emphasized evolution and adaptability, aiming to keep BCH competitive in a fast-moving industry.

Bitcoin SV (Satoshi’s Vision): Return to Origins

Led by Craig Wright, who controversially claims to be Satoshi Nakamoto, Bitcoin SV sought to restore what he described as the true original protocol—specifically, Bitcoin version 0.1.0 from 2009.

Key features of BCHSV included:

Wright positioned BCHSV as the purest form of digital cash—immutable, scalable, and resistant to developer-driven changes.

Community and Mining Support: A Divided Ecosystem

The split wasn’t just ideological—it played out across exchanges, mining pools, and public sentiment.

Who Supported Bitcoin Cash ABC?

Who Backed Bitcoin SV?

This imbalance created a dangerous scenario: while ABC had broader exchange and community support, SV held a temporary edge in raw mining power.

The Hash War: When Miners Become Warriors

A hash war occurs when competing chains use mining power aggressively to overpower one another—either by reorganizing blocks or launching sustained attacks.

In this case, tensions were heightened by the absence of effective replay protection. Although Bitcoin ABC implemented replay protection to prevent cross-chain transaction duplication, Bitcoin SV copied this mechanism in a way that effectively neutralized it—opening the door to replay attacks.

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A replay attack allows malicious actors to broadcast a transaction from one chain onto another, potentially leading to unintended double-spending. This risk was not theoretical—similar issues plagued the Ethereum/Ethereum Classic split in 2016.

Craig Wright further escalated tensions by suggesting he would not hesitate to launch a 51% attack on the ABC chain if necessary. While controversial, such an attack would allow SV miners to rewrite transaction history and invalidate ABC blocks.

The ABC team had several countermeasures ready:

Fortunately, no full-scale 51% attack occurred—but both sides engaged in symbolic mining battles, including the creation of empty blocks to assert dominance.

Post-Fork Reality: Winners, Losers, and Market Impact

Despite fears of chaos, the aftermath was relatively orderly—but impactful.

More broadly, the hash war had unintended consequences for the entire crypto market. Reports suggest that Bitmain diverted substantial mining resources from Bitcoin (BTC) to support BCH mining efforts. This shift weakened BTC’s network security temporarily and may have contributed to a sharp drop in Bitcoin’s price during that period—a reminder of how interconnected these ecosystems truly are.

Frequently Asked Questions (FAQ)

What was the main difference between Bitcoin Cash ABC and Bitcoin SV?

Bitcoin Cash ABC supported regular upgrades and innovations like CTOR and oracle integration, while Bitcoin SV aimed to preserve what Craig Wright called the “original” Bitcoin protocol with massive block sizes and minimal changes.

Did the hash war result in a 51% attack?

No confirmed 51% attack occurred. While both sides demonstrated mining strength, neither successfully rewrote significant portions of the opposing chain.

Which chain is considered “real” Bitcoin Cash today?

Today, Bitcoin Cash (BCH) refers to the chain following the Bitcoin Cash ABC roadmap. The competing chain continues as Bitcoin SV (BSV) under its own ticker.

Why did exchanges back Bitcoin Cash ABC?

Exchanges prioritized user safety, market stability, and broad developer consensus. BCHABC had wider community adoption and stronger support from wallet providers and infrastructure teams.

Can dormant Satoshi-era coins be spent on Bitcoin SV?

While Craig Wright proposed reactivating old addresses, no such action has been successfully executed. Doing so would require access to private keys and raise serious ethical and technical concerns.

Is another hard fork possible in the future?

Hard forks remain a possibility in any decentralized network. However, lessons from 2018 have made developers more cautious about implementing contentious upgrades without broad consensus.

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Final Thoughts

The battle between Bitcoin Cash ABC and Bitcoin SV was more than a technical dispute—it was a clash of ideologies about decentralization, governance, and what it means to stay true to Bitcoin’s roots.

While Bitcoin Cash ABC prevailed in terms of exchange recognition and branding continuity, Bitcoin SV demonstrated that raw computational power can challenge even well-established consensus.

Ultimately, both chains continue to exist today—BCH as a scalable digital currency focused on usability, and BSV as a niche player pushing extreme on-chain scaling. Their rivalry serves as a powerful case study in blockchain governance, miner influence, and the unpredictable nature of decentralized networks.


Core Keywords:
Bitcoin Cash ABC, Bitcoin SV, hard fork, hash war, blockchain scaling, CTOR, proof-of-work, cryptocurrency

Note: This article reflects historical events in cryptocurrency development. It does not constitute financial advice.