A public optimisation challenge run by StarkWare, Yukon Research and Eigen Labs demonstrated that AI-powered solvers can lower the estimated GPU cost of crafting a quantum-safe Bitcoin transaction from about $320 to $67 in just one week.
Quantum-safe Bitcoin: the problem and the first step
Bitcoin’s security relies on elliptic-curve cryptography, which could become vulnerable if large-scale quantum computers reach a threshold known as “Q-Day.” To pre-empt this risk, StarkWare designed a novel transaction format that replaces the usual ECDSA signature with a hash-based proof that can be verified by miners. The inaugural quantum-resistant transaction, mined on mainnet last month, required roughly 3,100 GPU-hours, translating to an estimated $320 expense under the hardware assumptions used.
The optimisation challenge and AI’s role
The Quantum-Safe Bitcoin Optimization Challenge invited participants to accelerate the brute-force search that runs on a user’s GPU before the transaction is broadcast. Because the construction must find a hash that fits an extremely narrow pattern—about one in 70 trillion attempts—the speed of candidate verification directly determines the compute cost.
During the contest, the best benchmark leapt from 146 million verified candidates per second to more than 820 million on an RTX 4090, thanks to 62 code improvements across two tracks. The most notable achievements came from teams that integrated large-scale language models. Anthropic’s Opus 5 and Fable 5.1 claimed the top records, while OpenAI’s GPT-6 Astra, Grok 4.6 and Kimi followed closely.
Cost implications and limits of the current approach
StarkWare reports that the $67 figure is an estimate based on the specific hardware configuration and the latest record-breaking code. It is not a market price, and the number will shift each time a solver improves performance. Moreover, the quantum-safe transaction format is non-standard; it must be sent directly to a miner and only protects funds whose public key has not yet been revealed on-chain. Consequently, the company stresses that a soft fork—an upgrade to Bitcoin’s consensus rules—remains the preferred long-term solution for network-wide quantum resistance.
Industry reaction and next steps
The dramatic cost reduction arrives as custodians and exchanges, including major players like Coinbase, draft post-quantum custody strategies. While the optimisation contest showcases the potential of AI to accelerate cryptographic engineering, the broader Bitcoin community still faces the challenge of integrating quantum-resilient mechanisms without disrupting the existing ecosystem.
Why it matters
Lowering the compute cost of a quantum-safe transaction makes experimental deployments more accessible for developers and researchers, accelerating the testing of post-quantum safeguards. The involvement of advanced AI models highlights a new frontier where machine-learning tools can be applied to hard-core cryptographic problems. However, without a consensus-level upgrade, such transactions remain a stopgap, underscoring the urgency for coordinated protocol changes before quantum computers become capable of compromising Bitcoin’s core security.
