Approximately 3,100 GPU-hours and $320 in compute costs were required to complete the first Quantum-Safe Bitcoin transaction on mainnet, demonstrating the technology’s potential while also highlighting its current impracticality, StarkWare says. StarkWare, Yukon Research, and Eigen Labs are now addressing this challenge with the launch of the Quantum-Safe Bitcoin Optimization Challenge, offering $20,000 in prizes to developers and researchers.
Two months after Avihu Levy published the QSB design in April 2026, the first mainnet transaction was mined on August 26th, showcasing a rapid transition from theory to practice. Improving the speed of this off-chain computation offers Bitcoin another option to study, test, and prepare for potential quantum threats.
QSB Design Achieves Bitcoin Mainnet Transaction
The challenge seeks contributions from developers, researchers, and artificial intelligence agents focused on improving the GPU computation underpinning Quantum-Safe Bitcoin, with the goal of making a potential quantum attack fallback more feasible. Currently, approximately 3,100 GPU-hours are required to construct a single QSB transaction, a figure the challenge aims to substantially lower.
The launch follows the successful mining of the first QSB transaction on August 26th via MARA’s Slipstream service, a milestone achieved with engineering from Tomer Giladi and building on research Avihu Levy published in April 2026. This initial transaction demonstrated the viability of hash-based quantum protection within Bitcoin’s existing consensus rules, requiring no protocol upgrade or soft fork.
While QSB currently functions as a last-resort option, protecting only the specific transaction construction and not retroactively securing exposed public keys, reducing its computational burden is a critical step toward broader usability, according to StarkWare. Despite the mainnet success, QSB transactions remain nonstandard, necessitating direct submission to a miner, and are currently expensive to generate; the compute cost of the first transaction totaled $320, separate from standard Bitcoin fees.
The collaborative challenge underscores a preference for a future soft fork as the long-term solution for efficient quantum protection on Bitcoin, but recognizes the immediate need to explore all viable options. Participants are encouraged to focus on optimizing the GPU computation, potentially unlocking a more practical pathway to quantum-resistant Bitcoin transactions.
$20,000 Challenge Targets QSB GPU Computation
A $20,000 prize pool now incentivizes optimization of the computationally intensive process behind Quantum-Safe Bitcoin transactions, with StarkWare providing $20,000 in prizes and Yukon offering an additional prize. The current process demands approximately 3,100 GPU-hours, effectively requiring a fleet of around 100 GPUs to complete a single transaction. This computational burden translates to a separate cost of roughly $320, distinct from standard Bitcoin transaction fees, and represents a significant barrier to practical implementation.
The challenge invites submissions focused on improving the efficiency of this off-chain computation, with a benchmark, fixed interface, and verification rules available to guide participants. A leaderboard will track progress, and the challenge page details the prize schedule and submission process. By reducing the resources needed for QSB transaction construction, developers can contribute to a more readily available fallback option as the Bitcoin community explores longer-term, protocol-level quantum resistance. Participants can join the Quantum-Safe Bitcoin Optimization Challenge and compete for the available prizes.
Benchmark Measures Verified Candidates Per Second
The benchmark used to assess Quantum-Safe Bitcoin transaction optimization focuses on maximizing independently verified candidates per second on a single GPU, a critical metric for reducing computational demands. This evaluation centers on two key workloads within QSB’s off-chain search process: transaction pinning and subset selection, both intensive tasks involving billions of candidate evaluations. Each candidate undergoes a rigorous process of nine omissions from 150 signature pushes, followed by reconstruction of a roughly 9.9 KB preimage and subsequent SHA-256 hashing and secp256k1 public-key recovery.
Participants in the optimization challenge can pursue several avenues for improvement, including refinements to search and hashing algorithms, focusing on combinatorial enumeration and reuse of intermediate results. The benchmark also encourages exploration of efficient elliptic-curve arithmetic, specifically scalar multiplication, point addition, and batch inversion techniques. Optimizing GPU execution, managing register pressure, memory traffic, occupancy, and synchronization, is another key area for potential gains.
Correctness is paramount; every submitted candidate hit is independently reconstructed on a CPU, with timing controlled by the judging system and ranked runs utilizing fresh, unpredictable problem instances. These checks ensure comparability between submissions and validate the effectiveness of optimizations. The challenge is also designed to facilitate allowing developers and teams utilizing AI-assisted coding agents to propose changes, measure their impact, and iterate against independently verified results. According to documentation from the QSB repository, improvements that transfer to the production implementation could reduce the GPU-hours needed for the corresponding searches.
Optimized QSB Offers Practical Quantum Fallback
The initiative follows the publication of the QSB design by Avihu Levy in April 2026 and a subsequent mainnet transaction completed roughly two months later in August, demonstrating a rapid transition from theoretical design to practical implementation. While QSB is positioned as a limited, last-resort option, not a comprehensive quantum-proof solution for the entire Bitcoin network, improvements to its efficiency offer a valuable tool for study and preparation as the community explores broader, protocol-level protections.
The challenge emphasizes that QSB protects only specific transaction constructions and does not retroactively secure exposed public keys, nor does it currently benefit from standard Bitcoin relay protocols, requiring direct miner submission, the company says. The challenge’s benchmark, rules, and leaderboard are publicly available, encouraging submissions that adhere to a fixed interface and verification process.
Participants are expected to review these guidelines before submitting their implementations, with the ultimate goal of generating quantum-safe Bitcoin transactions at a lower cost and contributing to the ongoing development of resilient cryptographic solutions for the network. StarkWare and Yukon Research each contribute funds to the challenge, with Yukon also offering an additional prize to further incentivize participation and innovation within the challenge.
Source: https://starkware.co/blog/quantum-safe-bitcoin-optimization-challenge/
