Research Proposal Outlines Quantum-Resistant Bitcoin Transactions Without Protocol Changes

A research proposal published on April 9, 2026, introduces a method to make Bitcoin transactions resistant to quantum computing attacks without requiring changes to the network's core protocol. The paper, titled “Quantum-Safe Bitcoin Transactions Without Softforks,” was authored by Avihu Levy of StarkWare.

It describes a scheme known as Quantum Safe Bitcoin, or QSB, which aims to address potential vulnerabilities in Bitcoin's current cryptographic design.

Bitcoin's standard transactions use ECDSA signatures based on the secp256k1 elliptic curve. Quantum computers running Shor's algorithm could potentially solve the discrete logarithm problem, allowing attackers to forge signatures and access funds. The QSB proposal seeks to mitigate this risk while maintaining compatibility with the existing Bitcoin protocol.

The QSB system shifts security from elliptic curve assumptions to hash pre-image resistance. It employs ECDSA only for verification purposes. This design builds on prior work called Binohash, which integrates one-time signature schemes into Bitcoin Script.

Core Mechanism of QSB At the heart of QSB is a hash-to-signature puzzle.

The system generates a hash of a transaction-derived public key using RIPEMD-160 and uses the output as a candidate ECDSA signature. Only a small fraction of such hashes comply with the formatting rules for valid ECDSA signatures, which creates a proof-of-work condition.

The paper estimates the probability of finding a valid hash at approximately 1 in 2^160, based on the hash function's output space.

This rarity ensures that generating a valid signature requires significant computational effort, akin to proof-of-work in Bitcoin mining. Successful implementation would protect transaction security without needing network-wide upgrades.

Background and Context Concerns about quantum computing threats to cryptocurrencies have prompted various research efforts.

Quantum computers could undermine public-key cryptography systems like ECDSA if they achieve sufficient scale. The QSB proposal offers a potential solution that avoids softforks, which are protocol changes requiring community consensus. StarkWare, Levy's employer, focuses on scalable blockchain technologies.

The proposal is available on GitHub for public review. As of April 12, 2026, no implementation details or adoption timelines have been announced. This development occurs amid ongoing discussions in the cryptocurrency community about long-term security.

Bitcoin's protocol has evolved through upgrades, but quantum resistance remains an emerging priority. Further analysis will determine the proposal's feasibility and integration path.