Crypto Insights
Using STARK-Based NTC and NIWA for Efficient Post-Quantum Bitcoin Signatures
Bitcoin Core developer Ethan Heilman emphasized the need for Bitcoin to adopt post-quantum (PQ) signatures to defend against quantum computing threats. He proposed using STARKs to implement Non-Interactive Transaction Compression (NTC) and Non-Interactive Witness Aggregation (NIWA) to make PQ signatures more efficient. These techniques can significantly reduce transaction size, helping mitigate scalability and centralization concerns, thereby preserving Bitcoin’s on-chain payment functionality and decentralization. The proposals are currently being explored in this Bitcoin Improvement Proposal and related research in *SNARKs and the Future of Blockchains.*
SwiftSync Cuts Initial Block Download Time by 80%
Sebastian Falbesoner published a sample implementation and performance results of SwiftSync, a new method initially proposed by Ruben Somsen that reduces Initial Block Download (IBD) time from 41 hours to just 8—over 5x faster. More details in this post.
SwiftSync speeds up UTXO database construction using a “hints file” from synced nodes. This file lists which outputs will still be unspent at a specific block. That block is called the terminal SwiftSync block. To sync, a user downloads the hints file and processes blocks up to the terminal block. They only store outputs if the file says those outputs will remain unspent. This avoids the need to add and later remove many entries during initial block download (IBD), saving time and resources.
Adds Fee Rate Forecaster Manager for Better Bitcoin Fee Estimation
A PR by developer Ismaelsadeeq introduces a new Fee Rate Forecaster Manager to upgrade Bitcoin Core’s fee estimation logic. The change adds a FeeRateForecasterManager class that can register multiple fee estimators for greater flexibility.
The previous CBlockPolicyEstimator, which relied solely on confirmed transactions, is now one of several forecast sources. A new MemPoolForecaster can analyze unconfirmed mempool transactions, enabling quicker and more accurate response to changing fee conditions.
secp256k1lab: Python Library Launched for Prototyping
Bitcoin developer Jonas Nick released an initial version of secp256k1lab (GitHub repo), a Python-based insecure implementation of the secp256k1 elliptic curve and related cryptographic schemes. Designed for prototyping, experimentation, and educational use, it supports low-level arithmetic, BIP-340-compliant Schnorr signatures and key generation, and ECDH key exchange.
This library serves as a reference implementation for ChillDKG, an ongoing BIP proposal, aiming to avoid redundant work and provide a unified secp256k1 interface for multiple BIPs. It's currently integrated as a subproject in the ChillDKG repo, though whether it should be included in the official BIP libraries is still under discussion.
Decentralized Mempool and Package Relay Are Key to Bitcoin’s Censorship Resistance
Bitcoin Core contributor and maintainer Gloria Zhao emphasized the importance of a decentralized mempool structure for censorship resistance in a recent interview with Bitcoin Magazine. Since each node runs its own mempool, no centralized authority can dictate which transactions get relayed or blocked.
To further improve efficiency and censorship resistance, she is working to implement Package Relay. This enables broadcasting interdependent transactions as a bundle, improving efficiency in complex use cases like opening Lightning channels, anchor outputs, and Replace-by-Fee (RBF). It also enhances censorship resistance: if a miner might otherwise ignore or censor a single transaction, bundling it with others raises the cost of refusal, reducing selective censorship risks.
OPNEXT 2025: Scaling Bitcoin for Developers and Builders
The second OPNEXT conference was held on April 11–12, 2025, bringing together Bitcoin developers and founders to explore scaling solutions across the Bitcoin tech stack. Highlights included: CTV + CSFS (Jeremy Rubin), Great Consensus Cleanup (Antoine Poinsot), Vaults for L1 Security (Sean Ryan), BitVM Practical and Economic Tradeoffs (Ekrem Bal).
BOB Integrates deBridge, Unlocking Cross-Chain DeFi for Bitcoin
BOB announced its Hybrid Layer 2 has integrated with deBridge, a high-speed cross-chain protocol. The integration connects BOB with over 20 EVM and non-EVM chains, including Solana, Berachain, Hyperliquid, and Sonic—unlocking new DeFi liquidity channels for Bitcoin.
With deBridge’s Interoperability-as-a-Service (IaaS), BOB gains fast bridging, cross-chain messaging, secure asset custody, and easy widget/API integrations. deBridge’s zero-TVL model and intent-based design offer low-latency, MEV-resistant cross-chain interactions.
BitVMX FORCE: Boosting Bitcoin Compute with BitVMX
Fairgate, Rootstock Labs, and Input | Output (IO) jointly launched BitVMX FORCE—a collaboration to expand Bitcoin’s computing power through the BitVMX framework. The effort focuses on driving research, standardizing the protocol, and aligning BitVMX with future Bitcoin soft forks as a leading programmable transaction framework.
Delbrag: Reducing BitVM On-Chain Costs with Garbled Circuits
Jeremy Rubin’s draft paper Delbrag introduces enhancements to BitVM-style constructions using Yao’s Garbled Circuits. The Delbrag design aims to significantly cut on-chain costs by integrating garbled circuit logic into BitVM-type systems—an evolution intended to improve efficiency in verifiable computation on Bitcoin.
ColliderVM: STARK-Based Stateful Bitcoin Computation Without Fraud Proofs
Researchers from StarkWare and the Weizmann Institute introduced ColliderVM, a system enabling stateful computation on Bitcoin without relying on fraud proofs. ColliderVM addresses a key challenge in BitVM-style systems: achieving computation under the same trust assumptions without needing onlookers to ensure validity through fraud proofs.
Instead of Lamport or Winternitz signature-based storage, ColliderVM uses hash collision-based commitments, inspired by ColliderScript but optimized for performance with fewer hash evaluations. Researchers claim that the resulting STARK proof lengths are nearly practical for Bitcoin Script.
Decentralized Publisher SilentBerry’s Book Now Readable On-Chain
SilentBerry, a decentralized publishing platform, built on the RGB++ protocol, launched a presale of book Saving Democracy earlier this year. Now, holders of the book’s Gold, Silver, and Bronze Berries can read it online.
SilentBerry uses the Spore protocol on CKB to issue on-chain assets in the form of Digital Objects (DoBs). As a decentralized publishing platform, SilentBerry’s NFT model offers a one-stop solution for authors and readers to issue content assets, invest in them, and share in the revenue.
Top Reads on Blockchain and Beyond
Free Banking and Its Connection to Ecash
Cashu: Bitcoin Freebanking introduces the concept of free banking and ties it to current developments in the Bitcoin space, focusing on practical applications involving ecash and the Cashu protocol.
The U.S. free banking era spanned roughly from 1837 to 1863, during which private banks issued their own banknotes without central oversight. Backed by reserves of gold and silver, these notes were easier to carry, safer, and faster to transact with than precious metals themselves.
The author compares Bitcoin to gold, noting that while Bitcoin has no physical weight, it still comes with technical hurdles and transaction fees in daily use. Free banking on Bitcoin could help address these issues using technologies like the Lightning Network to cut costs and boost efficiency.
The piece further explains how free banking can be implemented on Bitcoin, covering the ecash concept, the workings of the Cashu protocol, and its strengths—such as anonymity and low cost. It also explores how protocols can enable partial decentralization, reduce risk, and interface with the Bitcoin network. Use cases for Cashu include multinut payments, alternative tokens, event ticketing, and postage stamp functionality.
