Nic Carter Says Bitcoin Lags Ethereum in Quantum Resistance

Bitcoin transactions use elliptic-curve digital signatures to secure assets. A quantum computer running Shor’s algorithm could potentially derive private keys from public keys, putting older wallets and transaction security at risk. Ethereum, by contrast, has planned a mechanism allowing accounts to adopt quantum-resistant signatures, bringing corporate crypto treasury strategies and onchain governance capabilities into focus.

Google Quantum AI and other institutions published research on March 30, 2026, estimating that fewer than 500,000 physical qubits could crack a key in about nine minutes. Citi warned on May 18 that the potential attack timeline had shortened. Bit Digital had already announced on July 7, 2025, that it would sell about 280 Bitcoin and, alongside a $172 million fundraising, increase its holdings to 100,603 Ethereum.

Bitcoin uses elliptic-curve cryptography to protect assets and communications, but sufficiently powerful quantum computers could eventually break its current encryption. Experts say the more immediate danger is a “harvest now, decrypt later” strategy, in which attackers intercept and store large volumes of encrypted communications today, then recover sensitive historical data once the technology matures. The threat extends beyond wallet private keys.

Security experts and an early-stage venture investor have recently warned that historical communications and infrastructure data across the Bitcoin ecosystem may already be targets for quantum attacks. Ethereum has begun work on a post-quantum migration, but as of this report, neither Bitcoin nor related companies had publicly committed to specific safeguards, disclosed investment amounts or set completion dates. The upgrade timetable and division of responsibility therefore remain unclear.

Bitcoin currently relies on ECDSA and Schnorr signatures to secure asset ownership. A sufficiently powerful quantum computer could eventually use Shor’s algorithm to derive private keys from exposed public keys. Although the threat remains confined to laboratory experiments, migrating the network’s wallets, software and users would take considerable time, making early development of quantum-resistant safeguards critical to asset security.

Speaking at Paris Blockchain Week on April 16, 2026, Blockstream CEO Adam Back advocated introducing an optional upgrade first and giving users 10 years to move funds to quantum-resistant addresses. He estimated that a real threat remains at least 20 years away. Blockstream’s research division proposed a hash-based signature scheme in December 2025. The migration could also clarify whether the roughly 500,000 to 1 million Bitcoin attributed to Satoshi Nakamoto can still be moved.

Bitcoin uses elliptic-curve digital signatures to prove asset ownership. If a large-scale quantum computer could use Shor's algorithm to derive private keys, older addresses whose public keys have been exposed could be vulnerable to theft. Wall Street research and brokerage firm Bernstein said the risk is concentrated in Satoshi-era wallets holding about 1.7 million BTC, rather than posing an immediate threat to mining or the entire network.

Bernstein said on April 8, 2026, that Google had cut its estimate of the number of qubits needed to break the cryptography by about 20-fold to fewer than 500,000, but Bitcoin still had three to five years to upgrade. On April 13, the firm said BTC's nearly 50% retreat from its October 2025 peak of $126,198 had already priced in most of the quantum risk. The real challenge, it said, lies in securing community consensus and migrating wallets.

Quantum computers capable of breaking public-key cryptography could threaten Bitcoin signatures and asset ownership, making the technology a long-term market risk. Strategy, formerly MicroStrategy, co-founder and Executive Chairman Michael Saylor said banks, the internet and crypto assets all face the same pressure to upgrade, while Bitcoin could adopt quantum-resistant cryptography through updates to its nodes, wallets and protocol.

Saylor told Natalie Brunell’s “Coin Stories” on Feb. 23, 2026, that any quantum breakthrough posing a material threat was at least 10 years away. At a Mizuho event on April 8, he again said the risk was overstated and could be addressed through upgrades. He also said Bitcoin had likely bottomed at about $60,000 in early February; its price was around $71,200 when the report was published on April 9.

Quantum computers capable of using Shor’s algorithm to break elliptic-curve cryptography could derive private keys from public keys, threatening trillions of dollars in assets on Bitcoin, Ethereum and Solana. Although the risk is not imminent, migration could take years and would require decisions on legacy coins as well as community consensus. Early preparation has therefore become a core security priority.

A March 28, 2026, report said the Ethereum Foundation has operated a quantum research team since 2025 and is planning a phased rollout of post-quantum signatures and LeanVM. Bitcoin has proposed BIP360 to allow funds to move gradually to more secure addresses. Solana tested the Project Eleven-led Winternitz Vault in December 2025. The three networks still have no common timeline.

Quantum computers could threaten Bitcoin private keys and onchain assets if they become capable of breaking today’s elliptic-curve cryptography. BOLT Technologies founder Yoon Auh said adopting post-quantum cryptography would require more than a protocol overhaul. Large numbers of wallets, exchanges and holders worldwide would also need to migrate in coordination, testing the efficiency of decentralized governance.

The latest report focuses on whether Bitcoin governance can move quickly enough to address quantum risks, comparing the upgrade capacity of decentralized networks such as Ethereum with that of centralized systems. It gives no value for the assets at risk, potential date of a quantum attack or upgrade timetable. However, it stresses that assets held at legacy addresses could remain exposed if some wallets fail to migrate, even after the core protocol is updated.

Quantum computers could break Ethereum’s current elliptic-curve cryptography, threatening validator consensus, account signatures and onchain assets. Vitalik Buterin has identified four vulnerable areas in the protocol, including BLS signatures and KZG commitments. Upgrading Ethereum for quantum resistance is therefore critical to its long-term security and the protection of assets on the network.

Buterin has unveiled a comprehensive roadmap, while the Ethereum Foundation has formed a dedicated Post-Quantum team with the goal of completing protocol-level upgrades by 2029. The proposed measures include replacing vulnerable mechanisms with STARK proofs, introducing hash-based signatures into Lean consensus and exploring the use of SNARKs to reduce the performance burden of quantum-safe cryptography.