The Evolution of Bitcoin Cash - Every Upgrade from 2017 to 2025
Bitcoin Cash (BCH) has a fascinating history. Born as a fork of Bitcoin (BTC) in 2017, it wasn’t just a split—it was the continuation of the effort to achieve Bitcoin’s original vision as "peer-to-peer electronic cash," a form of money designed for the digital age. While Bitcoin has evolved into a trusted store of value, often referred to as "digital gold," Bitcoin Cash set out to focus on something different: being a fast, affordable, and reliable payment system for everyday use
From the very beginning, Bitcoin Cash prioritized low transaction fees and scalability, ensuring the network could handle a growing number of users without compromising performance. To achieve this, the BCH community embraced regular upgrades to improve scalability, security, and functionality. Initially, these upgrades occurred every six months, allowing for rapid innovation. In 2023, the network transitioned to yearly upgrades, providing a more predictable and stable development cycle while continuing to deliver meaningful improvements.
In this article, we’ll explore the key upgrades that have shaped Bitcoin Cash from its inception in 2017 to the latest advancements in 2024, as well as the exciting developments planned for 2025. Let’s dive into the journey of Bitcoin Cash and its commitment to innovation.
The Genesis of Bitcoin Cash (2017)
Bitcoin Cash was created on August 1, 2017, at block 478,558, as a hard fork of Bitcoin. The split wasn’t about competition—it was about different visions for the future. Bitcoin’s community wanted to preserve its stability and take a more conservative approach to upgrades, ensuring it remained secure and reliable. On the other hand, Bitcoin Cash’s community wanted to focus on scaling the network to handle more transactions and keep fees low, making it better suited for everyday payments.
Key Changes in the Genesis Fork
- Block Size Increase: The block size limit was increased from 1 MB to 8 MB, allowing Bitcoin Cash to process more transactions per block.
- Replay Protection: A new transaction signature hashing algorithm (SIGHASH_FORKID) was introduced to prevent replay attacks between Bitcoin and Bitcoin Cash.
- Emergency Difficulty Adjustment (EDA): A temporary difficulty adjustment algorithm was implemented to ensure blocks could be mined even with a lower hash rate.
- SegWit Rejection: Bitcoin Cash chose not to adopt Segregated Witness (SegWit), maintaining the original Bitcoin transaction structure.
Impact on Users
- Lower Fees: Users could send transactions for pennies, even during periods of high network activity.
- Faster Confirmations: Merchants and users benefited from faster transaction processing, making BCH ideal for point-of-sale payments.
November 2017 – Difficulty Adjustment Algorithm (DAA) Upgrade
To address the limitations of the Emergency Difficulty Adjustment (EDA), Bitcoin Cash implemented a new Difficulty Adjustment Algorithm (DAA) on November 13, 2017, at block 504,031.
Key Changes
- The new DAA adjusted mining difficulty every block based on the past 144 blocks, ensuring a consistent 10-minute block interval.
Impact on Users
- Stable Block Times: Users experienced more predictable confirmation times, even during periods of fluctuating hash rates.
- Improved Mining Incentives: Miners were incentivized to stay on the network, ensuring its long-term security.
May 2018 – 32 MB Block Size and Opcode Reintroduction
On May 15, 2018, at block 530,000, Bitcoin Cash underwent a major upgrade to increase scalability and reintroduce advanced scripting capabilities.
Key Changes
- Block Size Increase: The block size limit was raised from 8 MB to 32 MB, preparing the network for future growth.
- Reintroduction of Opcodes: Several previously disabled Bitcoin opcodes, such as OP_CAT and OP_SPLIT, were re-enabled to enable more complex contracts.
- Increased OP_RETURN Size: The maximum size of OP_RETURN data was increased from 80 bytes to 223 bytes, allowing for more metadata storage.
Impact on Users
- Massive Scalability: Users could transact without worrying about congestion or high fees, even during peak activity.
- Tokenization and Metadata Storage: Businesses could issue tokens and store metadata directly on the blockchain, enabling new use-cases like loyalty programs and digital collectibles.
November 2018 – OP_CHECKDATASIG (CDS), Canonical Transaction Ordering (CTOR), and Minimum Transaction Size
On November 15, 2018, at block 556,766, Bitcoin Cash introduced two major upgrades: OP_CHECKDATASIG (CDS) and Canonical Transaction Ordering (CTOR). This upgrade also led to a contentious hard fork, resulting in the creation of Bitcoin SV (BSV).
Key Changes
- OP_CHECKDATASIG (CDS): Allowed BCH scripts to verify signatures against external data, enabling oracles and other advanced use-cases.
- Canonical Transaction Ordering (CTOR): Changed the transaction ordering within blocks to a canonical order, simplifying block validation and propagation.
- Minimum Transaction Size: Introduced a rule requiring transactions to have a minimum size of 100 bytes, reducing spam and improving network efficiency.
Impact on Users
- Oracles and Smart Contracts: Developers could build applications that interact with external data, such as decentralized betting platforms or weather-based insurance.
- Faster Block Propagation: CTOR improved block propagation, reducing orphan rates and ensuring faster confirmations.
- Spam Mitigation: The Minimum Transaction Size rule reduced spam transactions, improving overall network performance.
May 2019 – Schnorr Signatures
On May 15, 2019, at block 582,680, Bitcoin Cash introduced Schnorr Signatures, a more efficient cryptographic signature scheme.
Key Changes
- Schnorr Signatures: Enabled signature aggregation, reducing transaction sizes and improving privacy.
Impact on Users
- Lower Fees: Users benefited from smaller transaction sizes, reducing costs.
- Improved Privacy: Multi-signature transactions became more efficient and private. Esecially when used with protocols like CashFusion.
November 2019 – Minimal Data Rule and Segwit Recovery
On November 15, 2019, at block 609,135, Bitcoin Cash introduced two key changes to improve efficiency and recoverability.
Key Changes
- Minimal Data Rule: Enforced stricter rules for transaction data to improve efficiency and reduce blockchain bloat.
- Segwit Recovery: Allowed users to recover funds sent to Segwit addresses by mistake.
Impact on Users
- Improved Efficiency: Transactions became more lightweight, reducing storage and bandwidth requirements.
- Fund Recovery: Users who accidentally sent BCH to Segwit addresses could recover their funds.
May 2020 – SigChecks and OP_REVERSEBYTES
On May 15, 2020, at block 635,258, Bitcoin Cash introduced SigChecks, a new mechanism for counting signature operations in transactions, and added the OP_REVERSEBYTES opcode.
Key Changes
- SigChecks: Replaced the legacy SigOps system, improving scalability and preventing denial-of-service (DoS) attacks.
- OP_REVERSEBYTES: Added a new opcode to reverse the byte order of data, enabling more advanced scripting capabilities.
Impact on Users
- Improved Scalability: Allowed the network to handle more complex transactions without risking DoS attacks.
- Enhanced Security: Reduced the risk of malicious transactions overloading the network.
- Enhanced Scripting: OP_REVERSEBYTES enabled developers to create more versatile smart contracts.
November 2020 – ASERT Difficulty Adjustment Algorithm
On November 15, 2020, at block 661,648, Bitcoin Cash replaced its DAA with the ASERT Difficulty Adjustment Algorithm.
Key Changes
- ASERT DAA: Adjusted mining difficulty every block using an exponential moving average, ensuring consistent block times.
Impact on Users
- Stable Block Times: Users experienced more predictable confirmation times, even during large hash rate fluctuations.
- Improved Miner Confidence: Provided a more predictable mining environment, encouraging long-term miner participation.
May 2021 – Double Spend Proofs, Multiple OP_RETURNs, and Chain Limit Removal
On May 15, 2021, at block 687,456, Bitcoin Cash introduced several upgrades to enhance security and usability.
Key Changes
- Double Spend Proofs: Detected and broadcast double-spend attempts in real-time.
- Multiple OP_RETURNs: Allowed transactions to include multiple OP_RETURN outputs.
- Unconfirmed Transaction Chain Limit Removal: Removed the 50-transaction limit on chained unconfirmed transactions.
Impact on Users
- Improved Security: Merchants accepting zero-confirmation payments were alerted to double-spend attempts, reducing fraud risk.
- High-Frequency Applications: Gaming platforms and micropayment systems could process thousands of transactions without hitting chain limits.
May 2022 – Bigger Script Integers and Native Introspection Opcodes
On May 15, 2022, at block 733,000, Bitcoin Cash introduced two scripting upgrades: Bigger Script Integers and Native Introspection Opcodes.
Key Changes
- Bigger Script Integers: Increased the size of integers that can be used in scripts, enabling more complex calculations.
- Native Introspection Opcodes: Added opcodes that allow scripts to access transaction metadata, improving smart contract functionality.
Impact on Users
- Advanced Smart Contracts: Developers gained the ability to create more sophisticated on-chain applications.
- Improved Flexibility: Bigger integers and introspection expanded the range of use-cases for BCH scripting.
May 2023 – CashTokens and Smart Contract Extensions
On May 15, 2023, at block 792,000, Bitcoin Cash introduced CashTokens and covenant-like functionality to enable advanced transaction restrictions.
Key Changes
- CashTokens: Allowed for the creation of fungible and non-fungible tokens (NFTs) directly on BCH.
- Covenants: Allowed for advanced use-cases like time-locked vaults and recurring payments.
- Further Opcode Enhancements: Improved scripting capabilities for DeFi and DApps.
Impact on Users
- Tokenization: Users could mint and trade tokens for DeFi, gaming, loyalty points, and collectibles without relying on third-party platforms.
- Recurring Payments: Users could set up automated payments for subscriptions directly on-chain.
- Enhanced Security: Time-locked vaults prevented unauthorized spending, improving wallet security.
May 2024 – Adaptive Blocksize Limit Algorithm
On May 15, 2024, at block 850,000, Bitcoin Cash introduced the Adaptive Blocksize Limit Algorithm.
Key Changes
- Adaptive Blocksize Limit Algorithm: Dynamically adjusted the block size limit based on network demand, improving scalability.
Impact on Users
- Scalability: Adaptive blocksize ensured the network could handle high transaction volumes without congestion.
Looking Ahead: Future of Bitcoin Cash
Bitcoin Cash has exciting plans for 2025 and we'll be watching closely to see what upgrade make it into the upcoming May 2025 network upgrade.
Conclusion
Bitcoin Cash has come a long way since its fork from Bitcoin in 2017. By prioritizing scalability, low fees, and usability, BCH has evolved into a robust platform for payments, tokenization, and decentralized applications. With its regular upgrade schedule—first every six months and now yearly—Bitcoin Cash has consistently delivered meaningful improvements to its network.
As we look ahead to 2025, Bitcoin Cash is poised to further enhance its capabilities, ensuring it remains a competitive and innovative force in the blockchain space. Whether you're a developer, merchant, or everyday user, Bitcoin Cash offers a fast, reliable, and affordable solution for your needs.
Sources and Acknowledgments
This article was made possible thanks to the detailed documentation provided by the Bitcoin Cash community. For more information on the technical specifications of Bitcoin Cash upgrades, visit the Bitcoin Cash Node Upgrade Specifications website.