Bitcoin developer Matt Corallo estimates that BIP-54—a proposal aimed at fixing four long-standing vulnerabilities in the network—has an 80% chance of becoming Bitcoin’s next soft fork.
Bitcoin developer Matt Corallo estimates that BIP-54, a proposal aimed at fixing four long-standing network vulnerabilities, has an 80% chance of becoming Bitcoin’s next soft fork.
- The proposed upgrade will address weaknesses in mining difficulty adjustment, block validation, Merkle tree proofs, and duplicate coinbase transactions.
- BIP-54 currently has no confirmed activation date; however, estimates gathered by developers at TABconf suggest the upgrade may arrive in 2027, more likely in 2028 or later.
- Some developers have questioned whether Bitcoin should prioritize maintenance over new features, but Corallo believes this upgrade helps establish a clearer process for future soft forks.
Corallo discussed this proposal with Isabel Foxen Duke, head of the MARA Foundation, on MARA Foundation TV, explaining why developers might prioritize fixing existing consensus issues over introducing new features.
The proposal titled "Great Consensus Cleanup" traces its origins to work proposed by Corallo in 2019, which later evolved into a formal Bitcoin Improvement Proposal co-authored by developer Antoine Poinsot.
Although the upgrade has no confirmed activation date, Corallo believes it addresses a technical issue widely recognized by developers and requires no major changes to Bitcoin's functionality.
Corallo said, "We know there is a long list of things that really need to be cleaned up." He described these vulnerabilities as legitimate concerns, but not an immediate threat to the network.
BIP-54 proposes fixes for four Bitcoin vulnerabilities.
The official specification of BIP-54 outlines modifications to Bitcoin's difficulty adjustment rules, transaction validation procedures, Merkle tree structure, and coinbase transaction requirements.
One issue involves a vulnerability known as the timewarp attack, which could allow miners controlling a majority of Bitcoin's hashing power to manipulate block timestamps.
Bitcoin adjusts its mining difficulty approximately every 2,016 blocks, which is roughly every two weeks. An attacker could exploit the existing timestamp rules to artificially lower the difficulty, causing new blocks to be generated faster than intended.
The technical documentation for the proposal estimates that, under extreme conditions, an attacker could reduce the mining difficulty to its minimum level within 38 days.
To address this issue, BIP-54 introduces constraints on the timestamps at the beginning and end of each difficulty adjustment period, including a two-hour tolerance to accommodate normal fluctuations.
Another proposed amendment targets specially constructed blocks that require an unusually large amount of computational power to verify.
According to specifications, some blocks may take several minutes to process on high-performance computers and even several hours on less powerful machines, allowing malicious miners to slow down their competitors.
BIP-54 will limit certain signature verification operations to 2,500 per transaction. Its author estimates that this limit can reduce the worst-case block verification time by a factor of 40.
The third fix addresses a Merkle tree vulnerability related to transactions containing exactly 64 bytes of non-witness data.
Under certain conditions, such transactions may resemble internal nodes of a Merkle tree, potentially allowing attackers to deceive lightweight Bitcoin clients into accepting forged transaction inclusion proofs.
The proposed rule would render transactions of this specific size invalid, thereby eliminating the underlying ambiguity.
The final change addresses duplicate coinbase transactions. A coinbase transaction is a special transaction created by miners to claim the block reward.
BIP-54 will introduce new requirements for the coinbase transaction field to prevent historical transaction identification issues from reoccurring at future block heights.
The specification states that, under current rules, block 1,983,702 is the earliest future height at which a duplicate coinbase transaction could occur.
Bitcoin developers are divided over future upgrades.
Although Corallo is confident, the proposal has faced criticism from some developers who believe Bitcoin should prioritize upgrades that introduce new capabilities.
Paul Sztorc, co-founder and CEO of LayerTwo Labs, posted on X that activating BIP-54 is "a bit frustrating" and argued that the proposal is merely maintenance work without adding any functionality.
Sztorc said that developers he spoke with at the TABconf in Atlanta generally expect this cleanup proposal to become Bitcoin's next soft fork.
However, their estimates suggest a long wait, with the earliest prediction pointing to September 2027, and most expecting activation in 2028 or later.
This debate continues a long-standing divide over Bitcoin protocol changes since the activation of Taproot in November 2021.
In September this year, crypto.news reported Sztorc's concern that Bitcoin may struggle to activate further soft forks due to disagreements over how consensus changes should be approved.
He specifically mentioned OP_CAT, a proposed upgrade designed to restore an operation that allows Bitcoin scripts to combine data and support more complex spending conditions.
Other proposals, including OP_CHECKTEMPLATEVERIFY under BIP-119, have also faced similar challenges in gaining sufficient support within the Bitcoin ecosystem.
Meanwhile, quantum computing has also become another topic of discussion in the protocol. Coinbase recently outlined several potential solutions to protect Bitcoin from future quantum threats, including BIP-360 and its proposed Pay-to-Merkle-Root output structure.
Unlike these proposals, BIP-54 focuses on addressing weaknesses in Bitcoin's existing consensus rules.
Corallo hopes that BIP-54 establishes a soft fork activation process.
In addition to technical changes, Corallo believes this upgrade may help developers establish a more predictable process for future Bitcoin soft forks.
He explained that Bitcoin upgrades have historically involved difficult technical decisions, but disagreements over the activation method have become an equally significant obstacle.
During the Taproot deployment debate, participants disagreed on whether miners should signal support before activation or whether users should enforce an activation deadline.
Corallo stated that developers can use the BIP-54 deployment process to address similar disagreements and establish procedures that can be reused for future upgrades.
According to its official changelog, the proposal reached full specification status on May 22, 2026, but this status does not equate to network activation.
Its compatibility terms state that these changes will tighten existing validation rules while remaining compatible with non-upgraded nodes.
However, the author still encourages node operators to update their software in order to independently implement these proposed restrictions.
For miners, the document notes that Bitcoin Core versions 29.0 and 30.0 already include block template protections compatible with some of the proposed restrictions, while mining pools must ensure their coinbase transactions comply with the new requirements.