"Bitcoin quantum threat materializes"…Could zero-knowledge proofs be the solution?

As quantum computing advances accelerate, warnings have emerged that cryptographic systems for virtual assets, including Bitcoin (BTC), face a fundamental threat. Because existing public-key cryptography could be rendered ineffective by quantum computers, it is argued that if action is not taken now, the entire Web3 could be exposed to structural risk.

According to CoinDesk on the 17th (local time), Arpa Network CEO Felix Shi wrote in an op-ed that the quantum computing era is no longer a distant future and that roughly $4 trillion in Web3 assets, including Bitcoin, are potential targets. He noted that quantum computers can solve cryptographic problems in a short time that are practically unsolvable by existing supercomputers.

In fact, Google announced last December that its quantum chip Willow performed computations that would take a classical supercomputer 10^25 years in under five minutes. That corresponds to a time about 100 trillion times longer than the age of the universe. While quantum computing promises innovations in areas such as drug discovery and financial modeling, it is also evaluated as a technology that could undermine the foundation of modern cryptography.

Shi claimed that attackers are already collecting encrypted blockchain data in preparation for the quantum era. He said that investing in virtual assets is effectively an investment in the integrity of cryptographic technology, and quantum computing directly threatens that premise. According to a Human Rights Foundation report, about 6 million BTC are held in initially quantum-vulnerable accounts, including 1.1 million BTC in Satoshi Nakamoto's dormant wallet.

Both Bitcoin and Ethereum (ETH) rely on the elliptic curve digital signature algorithm (ECDSA). This algorithm is known to be vulnerable to the quantum algorithm Shor's algorithm. Shi argued that, in theory, it cannot be ruled out that quantum actors are already breaking Bitcoin.

Of course, some view the threat as exaggerated fear. Cypherpunk Jameson Lopp has mentioned that the fear of quantum computing itself may be a greater risk. However, Ethereum co-founder Vitalik Buterin estimated a 20% chance that quantum computers could break Ethereum by 2030 and acknowledged the need for preparedness.

Shi proposed zero-knowledge proof (ZK) technology as a solution. ZK cryptography enables verification without revealing the information itself, and he explained that using hash-based proofs or lattice-based proofs can achieve quantum resistance. In particular, zk-STARKs do not rely on elliptic curves that are vulnerable to quantum attacks.

However, quantum-resistant ZK proofs are large and heavy, resulting in high blockchain storage and verification costs. Nonetheless, they are evaluated as a realistic alternative that can progressively introduce quantum safety without an immediate, full protocol overhaul. It is meaningful in that it provides a transition path where legacy cryptography and quantum-safe cryptography coexist.

Quantum technology can offer opportunities as well as threats. Shi argued that the true randomness provided by quantum technology can eliminate manipulability in block proposer selection or decentralized lotteries. This could be an element that increases the trustworthiness of core Web3 mechanisms.

Shi emphasized that, due to the nature of distributed systems, upgrades to base layers like Bitcoin can take years, and responding after quantum actually breaks ECDSA would be too late. While the timing of the quantum era's arrival may be debatable, he insisted the direction is clear and that action must be taken now.