G7 Urges Quantum-Safe Shift as Crypto Industry Tests Defenses

A quantum computer capable of running Shor’s algorithm at scale could undermine the public-key cryptography securing online banking, cross-border payments, government communications and digital assets. Bitcoin may provide the earliest visible warning because its ledger is public and its assets offer attackers an immediate financial incentive. Experts say the larger obstacle is not the availability of post-quantum algorithms, but whether decentralized networks can coordinate a contentious migration before existing signatures become vulnerable.

The Swiss Bitcoin Institute said in a report published on Sept. 30, 2025, that a cryptographically relevant quantum computer could emerge within 10 to 20 years. Such a machine could put about 6.8 million Bitcoin at risk, worth roughly 600 billion Swiss francs and representing nearly one-third of total supply. The report cited a Hudson Institute estimate that a major quantum-enabled breach could inflict between $2 trillion and $3.3 trillion in indirect losses on the U.S. financial system.

Bitcoin uses elliptic-curve digital signatures to protect private keys and authorize transactions. If a large-scale quantum computer could use Shor’s algorithm to break public-key cryptography, assets could be transferred without authorization. The threat extends beyond Bitcoin, forcing Web3 to reassess the underlying security of wallets, nodes and cross-chain protocols.

The latest assessments indicate that quantum computers could threaten the security of Bitcoin private keys within the next 5–8 years. The Web3 ecosystem is therefore accelerating adoption of the post-quantum cryptography standards published by the U.S. National Institute of Standards and Technology (NIST) in August 2024. Reports have not disclosed the cost of the migration or a firm completion date.

Bitcoin and Ethereum rely on elliptic-curve digital signatures to secure transactions and asset ownership. If quantum computers become substantially larger and more stable, they could theoretically derive private keys. The U.S. Commerce Department’s support for the quantum industry therefore has implications beyond technological competition and is adding pressure on the crypto sector to accelerate its adoption of post-quantum cryptography.

As of July 20, 2026, the U.S. Commerce Department planned to invest more than $2 billion in nine quantum-computing companies to help scale the technology. The development has renewed concerns about the security of Bitcoin and Ethereum. Experts are calling for prompt planning of Post-Quantum Cryptography upgrades and closer coordination among governments, regulators and developer communities.

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.

Blockchains such as Bitcoin and Ethereum rely on elliptic-curve cryptography to protect private keys. A sufficiently powerful quantum computer using Shor’s algorithm could potentially break public-key cryptography and steal assets. The U.S. National Institute of Standards and Technology (NIST) released its first post-quantum cryptography standards on August 13, 2024, underscoring that migration is not an issue confined to any single cryptocurrency.

Recent reports cited security experts warning that AI is aiding quantum hardware design, error correction and algorithm research, potentially shortening the time blockchains have to prepare their defenses. There is currently no quantifiable amount of assets at risk or confirmed date by which such systems could be compromised. The industry must begin assessing exposed wallets, testing post-quantum signatures, and planning timelines for hard forks and asset migration.

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.