After Google unveiled its new Willow quantum chip in December 2024, much of the cryptocurrency industry considered the practical threat from quantum computing to be years away. While it is theoretically possible for quantum computers to break the SHA-256 mining algorithm and the ECDSA signature system used by Bitcoin, the current hardware is far from sufficient—Willow, for example, offers only 105 physical qubits, whereas millions would be required for real-world attacks. However, since the chip’s launch, Google has shown signs of taking these risks more seriously.
Google moves towards post-quantum security and industry readiness
Google has publicly announced its aim to reinforce its authentication services with post-quantum cryptography by 2029. The company points to advances in hardware and error correction technologies that now make such a transition more feasible. In its upcoming Android 17 operating system, Google is implementing post-quantum signature protection, while its Chrome browser now features support for post-quantum key exchanges. Google Cloud, meanwhile, is already offering post-quantum solutions to enterprise clients—reflecting a multi-layered approach to strengthening defenses against potential quantum attacks.
Quantum computers differ from classical machines in that they process information using qubits instead of bits, enabling them to work through a vast number of possibilities simultaneously. Although these advantages are not always apparent in everyday applications, quantum devices hold a theoretical edge in areas such as factoring large prime numbers—the backbone of modern cryptography. It is widely held that a sufficiently powerful quantum computer could crack codes deemed unbreakable by classical computers in a fraction of the time.
Bitcoin relies on the ECDSA algorithm for transaction verification, making it susceptible to threats identified by Google. Should a large enough quantum computer run Shor’s algorithm, it could derive private keys from publicly available wallet addresses. This scenario would make any revealed public key on the network a potential target for attackers, raising the stakes for robust post-quantum security.
Vitalik Buterin, co-founder of Ethereum, remarked ahead of the Willow chip launch that experts across the field had become more cautious about the implications of quantum computing, underscoring the need for swift and proactive action in this area.
Post-quantum transition strategies in Ethereum and Bitcoin ecosystems
The Ethereum ecosystem has spent more than eight years conducting structured engineering work to prepare for the post-quantum era. The Ethereum Foundation has laid out a clear transition roadmap, with routine developer testnets and plans for four major hard forks aiming to spread post-quantum upgrades across all layers. Its pq.ethereum.org project details stages ranging from key registration systems to a network-wide post-quantum consensus model, indicating a coordinated and transparent strategy.
Bitcoin, in contrast, has yet to launch a similarly coordinated or long-term initiative. Bitcoin’s decentralized nature and slow consensus process remain barriers to rapid security transitions. The last major cryptographic upgrade, Taproot, required years of community debate prior to adoption. Despite proposals for quantum-resilient solutions, key developers in the Bitcoin community have so far shown little inclination to prioritize them.
Nic Carter, founder of Castle Island Ventures, highlighted Ethereum’s roadmap as an example, arguing that Bitcoin still lacks a comprehensive strategy or timeline for post-quantum readiness. According to Carter, Ethereum is advancing with greater awareness in this domain, while Bitcoin currently has no open program or plan to address quantum computing threats.
According to research from leading analytics firm CoinShares, the number of vulnerable Bitcoin addresses—those that would truly be at risk in the event of a sudden quantum breakthrough—is currently quite low. Assets held in so-called Pay-to-Public-Key legacy addresses are scattered across hundreds of wallets, making coordinated attacks costly and time-consuming in practice.
Leading standards organizations such as NIST, cryptocurrency platforms, and major tech companies broadly agree that the quantum threat will grow over time. The Ethereum Foundation, after eight years of preparation, is poised to accelerate its migration process. Google has set its transition deadline for 2029. For its part, the Bitcoin community has yet to rally behind collective action, leaving the long-term consequences of this slower response to unfold in the coming years.
