BlackRock has recently contributed to the discussion on quantum computing with a report that emphasizes potential threats to the current cryptographic frameworks securing major cryptocurrencies like Bitcoin and Ethereum. While the report reassures that there is no imminent crisis for blockchain technology, it advocates for proactive measures to begin the transition to post-quantum cryptography before significant advancements in quantum computing lead to serious vulnerabilities.
The report, titled “Quantum Computing and Blockchains,” was written by key figures at BlackRock, including Will Su, Head of Digital Assets Research, and Robert Mitchnick, Head of Digital Assets. The authors identify quantum computing as a notable challenge to both cybersecurity and blockchain governance, especially for systems relying on elliptic curve cryptography (ECC).
“Quantum computing has garnered heightened interest, especially concerning its implications for blockchains and broader cyber infrastructure,” the authors noted. “We believe that while quantum computing presents risks, they can be managed with timely and effective upgrades to post-quantum cryptographic standards.”
Understanding the Risk for Bitcoin and Ethereum
Currently, there are no operational Cryptographically Relevant Quantum Computers (CRQC). However, advancements in the field suggest timelines are evolving. For instance, Google has set a deadline for large-scale post-quantum migration by 2029, and IBM is targeting similar goals between 2029 and 2033.
Although concerns mostly center around ownership rather than the mechanics of Bitcoin’s proof-of-work process, the report highlights that Bitcoin’s SHA-256 hashing function is regarded as resistant to quantum attacks. The primary risk area lies in digital signatures, which ensure ownership of assets. Presently, Bitcoin and Ethereum depend on ECC for validating ownership and authorizing transactions. While conventional computing would require millions to billions of years to crack 256-bit ECC, a sufficiently powerful quantum computer may exploit these cryptographic weaknesses much more quickly.
“The principles of contemporary cryptography face challenges in the quantum paradigm,” BlackRock states. “The efficiency of quantum computers arises not from speed alone, but from their capability to unearth complex patterns within large datasets and solve problems not feasible for classical systems.”
Navigating Bitcoin’s Transition to Post-Quantum Standards
For Bitcoin, BlackRock argues that transitioning to post-quantum cryptography is technically simpler than for many systems due to the straightforward goal of replacing the digital-signature algorithm. A significant challenge lies in achieving consensus across a decentralized network that resists rapid or centralized changes.
The report indicates that around 7 million BTC, approximately 35% of the total supply, are at risk of long-range quantum attacks, as these public keys are already exposed. This figure includes 1.9 million BTC from address types that are particularly vulnerable, as well as an additional 5 million BTC associated with addresses that have previously exposed public keys.
Furthermore, BlackRock discusses the complexity surrounding inactive or lost coins, with estimates suggesting that 2.3 million to 3.7 million BTC could be permanently inaccessible. This encompasses nearly 1.1 million BTC believed to belong to Bitcoin’s creator, Satoshi Nakamoto.
“We believe that transitioning cryptocurrencies to post-quantum standards is technically feasible, although it will require careful coordination and implementation,” the report concludes. “The process of agreeing on post-quantum cryptography protocols, executing upgrades on the blockchain, and coordinating migrations across the ecosystem is likely to extend over several years.”
Assessing Ethereum’s Complex Challenge
Ethereum presents a distinct scenario. While the network has a well-defined roadmap for migration, outlined by the Ethereum Foundation, its technical complexity is heightened by its proof-of-stake consensus mechanism, smart contracts, and various data layers.
The report identifies four key areas of vulnerability within Ethereum, as highlighted by co-founder Vitalik Buterin in early 2026:
- BLS signatures in the consensus layer
- KZG proofs in the data layer
- Externally owned account signatures
- Zero-knowledge proofs in the application layer
These vulnerabilities affect areas such as validator voting, data verification, user transactions, and application-level proofs, all of which depend on cryptographic methods susceptible to quantum attacks. BlackRock refers to Ethereum’s “L1 Strawmap,” which outlines seven network updates and hard forks scheduled between 2026 and 2029, with five directly addressing these quantum threats.
Future Outlook for Cryptocurrencies
BlackRock’s report adopts a measured stance on the risk posed by quantum computing. Instead of framing it as an immediate existential threat, the authors categorize quantum risk as one of the remaining “walls of worry” for digital assets. Successful transitions to post-quantum standards could enhance the resilience of these platforms over time.
“As quantum computing capabilities evolve, global cybersecurity infrastructure is approaching a crucial turning point,” the authors concluded. “Digital assets like Bitcoin and Ethereum are technically poised for migration. However, the critical challenge lies in coordinating timelines and systematically implementing upgrades across decentralized networks. It is less daunting to enhance current systems to meet quantum threats than it is to develop a CRQC from the current state of quantum technology.”
As of the report’s publication, Bitcoin was trading at $62,629.
