2025 Bitcoin Protocol Layer Full Review

From Quantum Defense to Core Rebuilding

Top 10 Bitcoin Technological Shifts Ranked by Impact (Bitcoin Optech 2025 Annual Summary and Interpretation)

The annual summary from Bitcoin Optech has always been regarded as a barometer of the Bitcoin technological ecosystem. It almost ignores price movements and narrative battles, instead continuously documenting technological evolutions that truly alter protocol boundaries, infrastructure structures, and engineering paradigms.

The 2025 report sends a very clear signal: Bitcoin is transitioning from a【Passive Defense System】to an【Active Evolving Network Facing Survival-Level Threats】. Over the past decade, Bitcoin’s core technological philosophy has been minimal changes + conservative upgrades. But in 2025, we see the community systematically addressing three fundamental questions for the first time:

If quantum computing truly arrives, does Bitcoin have an executable migration path?

If global regulation and infrastructure continue to centralize, who can still independently verify and mine?

If Bitcoin is to support billions of users, must scaling rely solely on “outsourced layer-two solutions”?

Core conclusion: Understanding the three keys of 2025, looking at the year as a whole, Bitcoin’s technological evolution exhibits three major structural features:

1️⃣ Defense Frontloading (Security First Long Horizon)

Quantum threats are entering the engineering roadmap from “academic hypotheses” for the first time, with security discussion timeframes extending from【current cycle】to【post-quantum era】.

2️⃣ Layered Functionality (Layered Expressiveness)

L1 insists on minimalism and stability, releasing programmability and scalability through soft forks and L2/L3; Lightning enters an “hot-swappable” engineering phase.

3️⃣ Infrastructure Decentralization (Lowering Verification Power)

Mining protocols, node synchronization, UTXO verification all reduce costs, explicitly counteracting physical and political centralization forces in the real world.

We have compiled the following 10 events, which are concentrated manifestations of these three major trends. I have excluded updates limited to partial performance optimizations, retaining only those technological shifts with structural impact on the ecosystem.

01

Quantum Threat: Bitcoin

Systematic Defense and Reinforcement Roadmap Against Quantum Threats

Status: Research Stage / Long-term Proposal

2025 marks a year of qualitative change in the Bitcoin community’s attitude toward quantum computing.

The landmark event is: BIP360 officially received a number and was renamed P2TSH (Pay to Tapscript Hash).

This is not an immediate “quantum-proof” upgrade, but a critical structural stepping stone: it allows output structures that do not expose public keys, reserving scripts and commitments for future quantum-safe signature migrations; simultaneously serving non-quantum scenarios (such as pure commitment Taproot use cases).

Meanwhile, community discussions are beginning to delve into implementable engineering details: using OP_CAT to construct Winternitz hash signatures; exploring STARK verification as a native script capability, optimizing on-chain costs for hash signature schemes (such as SLH-DSA / SPHINCS+).

Why is it ranked first?

Because it touches the mathematical foundation of Bitcoin. Once the elliptic curve discrete logarithm assumption is weakened: the security of historical UTXOs will experience “temporal layering”; dormant addresses and unupgraded wallets will become systemic risk sources; the network will face an unprecedented migration coordination challenge.

For long-term holders, this means: asset security is no longer just about “private key storage,” but whether you are within an upgradable path.

02

Bitcoin Soft Fork Proposals

Surge in Soft Fork Discussions: Building Blocks for Programmable Vaults

Status: High-density discussion / Draft stage

In 2025, discussions on soft forks are notably intense.

Core directions are highly aligned: under the premise of minimalism, enhance script’s “constraint capability” rather than “arbitrary computation capability.”

Representative proposals include:

CTV (BIP119)

CSFS (BIP348)

OP_TEMPLATEHASH / LNHANCE

OP_CHECKCONTRACTVERIFY (BIP443)

Various arithmetic and script recovery proposals

These are not aimed at DeFi or “complex on-chain logic,” but serve a more fundamental goal: enabling Bitcoin natively to support secure, verifiable, and standardized fund constraint structures.

The direct result is the maturation of native Vault models: delayed withdrawals, freeze windows, revocation paths, enterprise-level fund governance strategies.

From an asset perspective, this elevates “self-custody risk management” from operational habits to protocol expressiveness.

03

Resilient Rebuilding of Mining Infrastructure

Resilient Rebuilding of Mining Infrastructure

Status: Experimental implementation / Protocol evolution

If consensus rules determine “what Bitcoin is,” then mining infrastructure determines “who executes it.” In 2025, the mining layer sees key engineering progress:

Bitcoin Core 30.0 introduces an experimental IPC interface: replacing inefficient JSON-RPC; significantly reducing communication overhead between mining pools and Core; paving the way for deep integration of Stratum v2.

The core significance of Stratum v2 is: enabling transaction selection rights to be delegated from the pool to the miner when Job Negotiation is enabled.

In extreme regulatory or geopolitical environments, this directly relates to: whether certain transactions will be systematically excluded, and whether MEV will evolve into a centralized censorship tool.

Meanwhile, MEVpool’s exploration attempts to use: blinded block templates, multiple marketplace competition mechanisms, to avoid “MEV markets themselves becoming new centralized hubs.”

04

Bitcoin Soft Fork Proposals

Immunity System Upgrade: Vulnerability Disclosure and Differential Fuzzing

Status: Ongoing engineering practice

In 2025, the number of vulnerability disclosures recorded by Optech has increased significantly:

Bitcoin Core

LDK / LND / Eclair

Involving fund lockups, privacy leaks, and extreme theft risks

The most critical progress is: the scaled application of Differential Fuzzing, with Bitcoinfuzz discovering over 35 deep bugs within a year by comparing responses of different implementations to the same input.

This marks a mature system: short-term “more problems,” long-term “significantly enhanced immunity.”

05

Bitcoin’s Lightning Network

Lightning Network Splicing: “Hot Update” of Channel Funds

Status: Cross-implementation experimental support

Splicing is the biggest breakthrough in LN usability in 2025. It solves a long-standing pain point: dynamically adding or removing funds without closing the channel.

Currently: LDK, Eclair, Core Lightning have all implemented experimental support and completed multiple interoperability tests.

Its significance lies in: reducing channel management complexity, decreasing payment failure rates, and clearing engineering hurdles for “LN as a daily payment account.”

06

Node Cost Revolution

Verification Cost Revolution: Running Full Nodes on “Civilians’ Devices”

Status: SwiftSync prototype / Utreexo BIP draft

The true moat of decentralization is the distribution of verification rights. In 2025, two technologies are directly impacting the threshold for full nodes:

SwiftSync: restructuring UTXO write logic during IBD, only writing to chainstate if unspent after IBD completion; in sample implementation, accelerating IBD by over 5 times.

Utreexo (BIP181–183): using Merkle Forest accumulators, allowing nodes to verify transactions without storing the full UTXO set.

This means: low-power devices, mobile nodes, edge networks can become independent verifiers.

07

Reshaping the Bitcoin Fee Market

Cluster Mempool: Underlying Scheduling for Fee Market Reshaping

Status: Near release (Staging)

Cluster Mempool is a key underlying upgrade in Bitcoin Core 31.0.

Using structures like TxGraph:

Systematically handle complex transaction dependencies; improve stability of block template construction.

The direct result is: more predictable fee rate estimation, behavior of CPFP / RBF more aligned with expectations, and smoother fee curves during congestion.

08

Refined Governance of P2P Propagation Layer

Refined Governance of P2P Propagation Layer

Status: Policy updates / Continuous optimization

In 2025, a surge in low-fee transactions forces P2P strategy adjustments:

Core 29.1 lowers default minimum relay fee to 0.1 sat/vB.

Erlay continues to reduce bandwidth consumption.

Sharing of block templates and continuous optimization of compact block reconstruction.

The result is: further lowering of node operation thresholds, more balanced network propagation, and low-fee transactions are no longer systematically “dropped.”

09

Debate on OP_RETURN and Block Space “Commons Tragedy”

OP_RETURN and Block Space “Commons Tragedy” Debate

Status: Mempool Policy change (Core 30.0)

Core 30.0 relaxes OP_RETURN restrictions:

More outputs

Removing some size limits

This is a policy-layer (non-consensus) adjustment but has real impact: it influences how easily transactions propagate, indirectly affecting block space competition structure.

The core debate is: should Bitcoin remain neutral toward “non-payment uses”?

The answer remains contested.

10

Bitcoin Kernel: Core Code Rebuilding

Bitcoin Kernel: Modular Rebuilding of Core Code

Status: Architectural overhaul / C API release

This is the most easily overlooked but deeply impactful development of 2025.

Bitcoin Core introduces Bitcoin Kernel C API:

Decoupling consensus verification logic into independent components.

External projects can directly reuse the “official verification engine.”

The significance lies in: reducing consensus divergence risks, enhancing overall ecosystem security, and providing “factory engines” for analysis tools and wallet backends.

Finally:

To sum up 2025 in one sentence: Bitcoin is starting to seriously design for【living long enough】.

Not for the next cycle, but for the next stage of technological civilization. **$QTUM **$BCH