Quantus Weekly: The Cost of Breaking Bitcoin Keeps Dropping

The cost of breaking Bitcoin’s signatures keeps dropping.

Some breakthroughs are secret, others are happening in public.

In March, Google Quantum AI published a paper that cut the resource estimate for attacking elliptic-curve signatures by 10x.

Then they did something strange.

They validated the optimized circuits with a zero-knowledge proof and kept the circuits themselves secret. The blog post said they “engaged with the U.S. government.”

A ZK proof is an information hiding tool. This is the first time I’ve seen a ZK proof used to hide information related to national security.

Justin Drake co-authored the paper and said the context around the secrecy did not sit well with him, and that he was limited in his ability to whistleblow.

Recently, @eigenlabs took the core of the problem and turned it into a public scoreboard called ECDSA (dot) fail.

Anyone can submit a circuit. The verifier, repurposed from Google’s own ZK harness, scores it.

An undergrad with no formal quantum training and a Codex subscription used agents to get within 50% of Google’s withheld number. An 18-year-old spent a weekend and $10K of AI spend with a custom agent swarm and pushed it to 80%. Then they opened it to the public. Within three days the leaderboard passed Google’s reference point.

This does not break Bitcoin today.

But it is proof that AI agents are shaving the cost of Shor’s algorithm in the open, every day, and small optimizations compound.

The open source community has made above a 40% improvement over Google’s circuit at the time of writing this.

Pair this trend with a breakthrough in any of the hardware approaches to engineering quantum computers and Q-Day is here.

So we should talk about it.

Last weekend we hosted QDay at @ns. Over 220 people showed up: industry, academics, and builders, all working on one question.

How do public blockchains survive quantum computers?

We also published an accompanying report. The fastest way to get up to speed on the quantum threat to blockchains and the roadmap ahead.

Here’s what else we shipped this week:

Github Activity (27 merged pull requests):

Github Stats

Core Tech & ZK:

Switched from libp2p to litep2p, giving Quantus a leaner networking stack with lower overhead and more direct control over peer behavior.
Ran security audits and shipped fixes across the proving stack, covering Plonky2 and our ZK circuits.
Hardened the ML-DSA post-quantum signature implementation and finished an audit of the RPC code surface, reducing the node’s external attack surface ahead of mainnet.