Bitcoin BIP targets quantum resilience as 7 million BTC face risk

A new Bitcoin Improvement Proposal seeks to harden the network against quantum computers, though implementation faces steep technical hurdles.

A Bitcoin Improvement Proposal published Aug. 27 would add quantum-resistant cryptography to the network, a response to estimates that roughly 7 million BTC sit exposed to future quantum attacks.

"I still want Bitcoin to choose to do a soft fork and I expect we will get one," Eli Ben-Sasson, chief executive at StarkWare, said. "What today's successful transaction offers Bitcoin is a reassurance that holdings can be protected before that happens."

The proposal follows StarkWare's Aug. 26 test of the first quantum-safe Bitcoin transaction, mined in block 964,199 using the Quantum-Safe Bitcoin method. QSB relies on one-time Lamport signatures and hash functions rather than the elliptic-curve cryptography that a sufficiently powerful quantum computer running Shor's algorithm could break. The method costs roughly $150 to $200 per transaction and requires hours of proof generation across high-end graphics cards, StarkWare said.

The stakes are concrete. Coinbase's quantum advisory council estimated in June that about 7 million BTC could be vulnerable because of exposed public keys and address reuse. A soft fork remains the preferred long-term defense, Ben-Sasson said, while QSB protects individual holdings before any network upgrade.

Why the Upgrade Path Is Hard

The BIP faces implementation challenges. QSB cannot protect addresses with already-exposed public keys and currently requires transactions to be sent directly to miners, StarkWare acknowledged. Its larger transaction size makes the method unsuitable for normal Bitcoin payments at scale, and widespread use would add pressure on the network and push fees higher.

Ethereum Charts a Parallel Course

Ethereum developers have proposed a separate draft EIP to overhaul the staking deposit contract, expanding the maximum size of validator public keys from 48 bytes to as much as 8,192 bytes to enable future adoption of quantum-resistant signatures. The proposal also includes a function to halt new deposits using the current BLS signature scheme, providing a controlled transition path without a disruptive hard fork.

For Bitcoin holders, the near-term effect is limited: the BIP is a draft under review, and the specific quantum-resistant signature method will be defined in a separate future proposal. But the flurry of activity across Bitcoin and Ethereum shows the industry is preparing for a threat whose timeline remains uncertain. Ben-Sasson said the work should not be read as proof that Bitcoin is ready. "Huston, we've got a problem," he wrote on X, "and the way to fix it should be to get serious about serious soft forks."

This article is for informational purposes only and does not constitute investment advice.