Quantum

Google Cut the Estimated Qubit Threshold for Breaking Bitcoin by 20x

On March 31, Google's Quantum AI team published a whitepaper arguing that breaking elliptic-curve cryptography — the signature scheme securing Bitcoin — may require far fewer quantum resources than prior estimates. The headline number of fewer than 500,000 physical qubits is a 20x reduction from what was previously modeled. The '9-minute attack with 41% success rate' framing circulating in crypto media is a scenario estimate from secondary coverage, not Google's primary claim. What Google actually established is more significant and more durable: the hardware bar is materially lower than the industry assumed, and the case for post-quantum migration planning is now more urgent.

Mar 31, 2026

Four Bitcoin Proposals for Surviving a Quantum Attack

Google's March 31 whitepaper compressed the estimated qubit threshold for breaking Bitcoin's elliptic-curve cryptography by 20x. Bitcoin developers have known the threat was coming for years. There are now four concrete proposals in various states of development — BIP-360, SPHINCS+, SHRIMPS, and Hourglass V2. None are activated. None have a scheduled deployment. The governance problem may be harder than the cryptography problem.

Apr 5, 2026

Two Papers Reframe Bitcoin's Quantum Threat as Mostly Misunderstood

The week after Google's quantum paper compressed the estimated hardware threshold for breaking Bitcoin's cryptography, two academic papers pushed back on how the threat is being framed in crypto media. One found that a quantum 51% attack on Bitcoin mining would require star-level energy. Another replicated every major quantum factoring breakthrough of the past 20 years using a 1981 home computer, an abacus, and a dog. Neither dismisses the threat. Both refocus it on where it actually sits.

Apr 9, 2026

Bitcoin Quantum Prototypes Work Without Changing the Protocol

On April 10, Lightning Labs CTO Olaoluwa Osuntokun posted a working zk-STARK prototype to the Bitcoin developer mailing list that lets wallet owners prove key ownership without exposing their seed phrase — designed to rescue funds if Bitcoin ever disables Taproot key-path spending. The same week, StarkWare developer Avihu Levy published QSB (Quantum-Safe Bitcoin), a complete quantum-safe transaction scheme that works within existing legacy script constraints with no protocol changes required.

Apr 10, 2026

BIP-361 Would Freeze Bitcoin That Doesn't Migrate to Quantum-Safe Addresses

On April 15, a group of Bitcoin developers including Casa CTO Jameson Lopp published BIP-361, titled 'Post Quantum Migration and Legacy Signature Sunset.' The proposal builds on BIP-360's new quantum-resistant address type by adding a compelled migration deadline: three years after activation, no new sends to legacy addresses. Five years after activation, legacy signatures become invalid and any Bitcoin that has not migrated is permanently frozen. An estimated 5.6 million BTC, including Satoshi Nakamoto's 1.1 million coins, fall within scope. The proposal is in draft form with no activation timeline. The community response was immediate and hostile. Lopp himself said he hopes it's never needed.

Apr 15, 2026

Coinbase's Quantum Board Flags 6.9 Million Bitcoin as Vulnerable

Coinbase's Independent Advisory Board on Quantum Computing and Blockchain published its first position paper Tuesday. The 50-page report, authored by researchers from Stanford, UT Austin, the Ethereum Foundation, Eigen Labs, Bar-Ilan University, and UC Santa Barbara, identifies wallet-level cryptography as the primary vulnerability and estimates 6.9 million BTC sit in wallets where public keys are already visible on-chain. The board recommends migration begin immediately rather than wait for the threat to become urgent. NIST recommends migration by 2035; the report suggests that timeline may prove optimistic. Post-quantum signatures are tens to hundreds of times larger than current ones, which could increase block data costs by up to 38x. This is the first time a major US exchange has assigned a specific BTC-at-risk number and published a coordinated industry position.

Apr 22, 2026

Postquant Labs Shipped Quantum Protection Without a Bitcoin Soft Fork

On Tuesday, April 28, Postquant Labs announced Quip Network, a post-quantum Bitcoin wallet that uses Arch Network's Bitcoin-native smart contract layer to add WOTS+ hash-based signatures on top of Bitcoin's existing security. The product requires no soft fork, no consensus change, and no community vote. It is the first quantum-protection path that does not depend on the Bitcoin network coordinating a migration. The announcement lands six days after the Coinbase Advisory Board paper put the BTC-at-risk pool at 6.9 million coins, and three weeks after BIP-361 proposed freezing legacy-format coins on a five-year timeline. The wallet ships next week. The third-party audit is underway but incomplete. Arch Network is still early infrastructure. The sovereignty implication is significant regardless of those caveats.

Apr 28, 2026

Project Eleven's 15-Bit Quantum Bounty, Reproduced in 20 Python Lines

On April 24, quantum security firm Project Eleven awarded its 1 Bitcoin Q-Day Prize to Italian researcher Giancarlo Lelli for breaking a 15-bit elliptic curve cryptography key on publicly accessible IBM Quantum hardware using a variant of Shor's algorithm. The result was framed as the largest public quantum attack on ECC to date, a 512-fold increase over the September 2025 record. Within days, Bitcoin Core developer Jonas Schnelli reproduced the same result with 20 lines of Python and a random number generator. Security researcher Yuval Adam forked Lelli's repository, replaced the IBM Quantum calls with random bytes from /dev/urandom, and got byte-identical output. The Q-Day Prize headline does not survive technical scrutiny, but the underlying trajectory of quantum capability remains real. The OPNorange audience needs the calibration the headline did not provide: the threat is real, the timeline is uncertain, and the most aggressive demonstrations are not the data points that should drive your migration decisions.

Apr 30, 2026

Trump Executive Order Moves Federal PQC Deadline to 2031

On Monday, June 22, President Trump signed two executive orders on quantum computing: one setting a target of deploying a scientifically relevant quantum computer at a national lab by 2028, and one moving the federal post-quantum cryptography migration deadline from 2035 to December 2031. NIST must complete a pilot migration of federal systems by end of 2027. Federal civilian agencies must move high-value key-establishment systems to ML-KEM by end of 2030 and digital signature systems to ML-DSA by end of 2031. The orders cover federal agencies. They say nothing about Bitcoin. The 6.9 million BTC the Coinbase advisory board identified in April as sitting in quantum-vulnerable addresses has no equivalent mandate, no named enforcement authority, and no funded migration plan. Federal agencies get a 4-year acceleration and a compliance checklist. Self-custody Bitcoin holders get the same community debate they have been having since 2021.

June 23, 2026