Bitcoin Cash Upgrade v25.0.0
The Bitcoin Cash Node (BCHN) project has announced a major release version 25.0.0. It delivers four Cash Improvement Proposals (CHIP) that are consensus changes and a number of other enhancements, bugfixes and performance improvements on the main network (mainnet).
CHIP-2021-01 Restrict Transaction Version (v1.0)
CHIP-2021-01 Minimum Transaction Size (v0.4)
CHIP-2022-02 CashTokens (v2.2.1)
CHIP-2022-05 P2SH32 (v1.5.1)
The network upgrade is expected to take place once the median time past (MTP) [1] of the most recent 11 blocks is greater than or equal to UNIX timestamp 1684152000 (15th May 2023 at 12:00:00 UTC / 16:00:00 GST).
Announcement | Bitcoin Cash Node v25.0.0
Bitcoin Cash Network Upgrade Specification
Evaluation Process
MidChains has:
Evaluated what is changing?
Analysed the impact of the changes.
What is Changing?
v25.0.0
The proposed upgrade to the Bitcoin Cash peer-to-peer electronic cash system would enhance the enforcement of acceptable transaction version field values as a consensus rule. The current network relay rule would be replaced with a consensus rule to ensure compliance with the allowed transaction version field values. By including this in the consensus specification, it would be easier to track future Bitcoin Cash consensus specification upgrades. This would also facilitate future hard-fork upgrades that are non-breaking and backwards-compatible for non-node software.
The proposed update to the rule for minimum transaction sizes aims to reduce the burden on library and mining software while ensuring that users of Simplified Payment Verification (SPV) nodes are protected from potential attacks. The current consensus minimum transaction size of 100 bytes would be lowered to a new minimum size of 65 bytes. This new minimum size (65-byte), which is similar to the previous 100-byte minimum size, would apply to both coinbase and non-coinbase transactions in a uniform manner.
This proposal aims to enable the creation and use of tokenized assets on the Bitcoin Cash network. It proposes a set of new opcodes and transaction types that can be used to issue and transfer tokens on the network, such as creating loyalty points, digital art or other assets. The introduction of the two new token primitives on Bitcoin Cash: fungible tokens and non-fungible tokens will be deployed to enhance the Bitcoin Cash contract system. This is expected to bring several improvements such as cross-contract interfacing, support Decentralized Apps on Bitcoin Cash by way of the Bitcoin Cash Virtual Machine (VM), as well as supporting the development of higher-level interoperable token standards e.g., Simple Ledger Protocol (SLP).
This proposal aims to improve the security and functionality of Pay-to-Script-Hash (P2SH) transactions on the Bitcoin Cash network. It proposes changing the current P2SH address format from 20 bytes to a 32 byte variant to increase the number of possible address combinations, making the address scheme more secure and flexible. The 20-byte variant is known to have weakness against the birthday attack. This has prevented many decentralized applications from being created as they tend to be insecure and impractical to use.
Support for New ‘Chipnet’ Test Network (For Pre-Upgrade Testing)
Ahead of the mainnet upgrade, a new ‘chipnet’ test network has been added to enable testing of all the new upgrade features (such as CashTokens, P2SH-32). The chipnet was activated on 15th November 2022.
Double Spend Proof Notifications in the GUI Wallet
This feature allows users of the graphical user interface (GUI) wallet to receive notifications when a double spend attempt is detected on a transaction they are attempting to make.
BIP69 Input/Output Sorting in Bitcoin-tx Command Line Tool
This enhancement improves the functionality of the bitcoin-tx command line tool by implementing BIP69 input/output sorting, which can make transactions more efficient.
Enhancement for UI Tests in Test Framework
This feature improves the user interface (UI) testing capabilities of the Bitcoin Cash Node software by adding enhancements to the test framework.
Release instruction
Release 25.0.0 · bitcoin-cash-node/bitcoin-cash-node · GitHub
Impact Analysis
MidChains will support the Bitcoin Cash network upgrade. Node operators are required to upgrade their nodes to v25.0.0 or a newer version before 15th May 2023 as v24.x.0 software will expire on the same date. Users currently running v25.0.0 are not obliged to upgrade to v26.0.0, but it is advisable to do so. No action is required by clients who hold BCH and clients’ funds will not be impacted by this upgrade. Deposit, withdrawal, and trading will remain uninterrupted for BCH and BCHUSD during the time of the upgrade.
The upgrade is not explicitly noted to be contentious, however, the Bitcoin Cash Node team has stated their close working relationship with other software and hardware developers to ensure compatibility with the upgraded protocol. Efforts will be made to minimize disruptions to network operations and exchange connectivity. This suggests that efforts are being made to avoid a contentious hard fork that could result in a split in the network.
Impact on Client Funds: No impact to clients' funds post network upgrade. All transactions are expected to be processed without issue
Regulatory implications: None
Maturity / Market Capitalization: None
Security and Operations: Enhanced security and efficiency
Traceability / Monitoring: None
Exchange Connectivity and Demand: Potential increase in market participants
Type of Distributed Ledger Technology (DLT): No impact
Innovation and /Efficiency: Improved network performance in relation to speed and scalability
All potential operational and market risks identified in relation to the Bitcoin Cash network upgrade including potential network stability, possible vulnerabilities posed by malicious actors on the network’s security due to protocol changes, disruption to the network, and possible fluctuation in the price of BCH have been found not to have significant impact, as the Bitcoin Cash Node team have put measures in place to mitigate significant risks by giving priority to network security, maintaining traceability of transactions, and fostering innovation on the network. Prior to the announcements of the Bitcoin Cash network upgrade version releases, extensive testing has been conducted and further improvements are tracked in the Bitcoin Cash Node Project Gitlab Repository.
Upgrade Preparation
Node operators are required to upgrade nodes before 15th May 2023. No action is required by clients who hold BCH.
For more information, please refer to: Bitcoin Cash Upgrade - v25.0.0. and v26.0.0