A critical issue on the crypto horizon is the impact of quantum computing on blockchain security and digital assets. To unpick this topic, Digital Journal spoke with Rick Maeda, who is a Research Analyst at Presto Research. This is the research arm of Presto Labs, a quantitative trading firm that oversees +100M daily orders within the digital assets market. He is the co-author of the research paper: “Quantum Computing x Crypto: Everything You Need to Know.“
Maeda tackles key questions that crypto developers, investors, and policymakers need to be asking today about quantum computing’s potential to reshape the market.
Digital Journal: How close are we to a quantum computer powerful enough to break Bitcoin’s cryptography, and what signs should the industry be watching for?
Rick Maeda: Breaking the cryptographic foundations of Bitcoin requires a fault-tolerant quantum computer with millions of physical qubits, extremely low logical error rates, and the capacity to execute approximately 100 million fault-tolerant quantum gates. Current quantum processors remain in the hundreds of noisy qubits and have physical error rates on the order of 10⁻³.
The key indicator of progress is the emergence of Intermediate-Scale Error-Corrected Quantum (ISEQ) systems. These systems, while not yet capable of breaking ECC, would demonstrate sustained fault tolerance and meaningful improvements in logical error rates. The industry should monitor progress in error correction benchmarks and the achievement of logical error rates below 10⁻⁵ as a signal that such scaling is feasible.
DJ: Which current blockchain technologies are most vulnerable to quantum attacks, and why?
Maeda: Any protocol relying on elliptic curve cryptography (ECC) or RSA for digital signatures is exposed to quantum threats, due to the existence of Shor’s algorithm. Bitcoin and Ethereum, for instance, both rely on ECC and are subject to attack if sufficiently powerful quantum hardware becomes available.
While some wallet formats conceal public keys via hashing, public keys are ultimately revealed upon transaction broadcast. This creates a window during which a quantum adversary could derive the corresponding private key. Protocols or legacy wallet designs that expose public keys more broadly are particularly at risk. Ethereum’s account-based model results in long-term public key visibility, which increases surface area for future attack vectors.
DJ: What is Post-Quantum Cryptography (PQC), and how feasible is it to integrate PQC into existing blockchains?
Maeda: Post-Quantum Cryptography (PQC) refers to a class of cryptographic algorithms believed to be secure against quantum attacks. These schemes are based on hard problems such as lattice structures, hash-based constructions, or coding theory. Several such schemes have been standardised by NIST.
Despite their theoretical robustness, PQC schemes typically involve larger keys and signatures, increased verification costs, and more complex implementations. These trade-offs present challenges for blockchain protocols, which are often resource-constrained environments. One-time signature schemes, such as those based on the Lamport or Winternitz constructions, offer provable security but impose functional constraints due to their one-time nature.
Adoption of PQC is technically feasible and has begun in experimental projects and wallets. However, major protocols have not yet deployed these schemes at scale.
DJ: Could quantum computing give rise to a new generation of cryptocurrencies—and what would they look like compared to today’s assets?
Maeda: Quantum computing could motivate the emergence of new digital assets and protocols designed to incorporate quantum resistance from inception or to exploit novel capabilities enabled by quantum hardware.
These assets may adopt cryptographic primitives that are not only post-quantum secure but also more efficient or expressive in a quantum context. Potential features include the integration of quantum-derived randomness, enhanced privacy through quantum-secure multiparty computation, and the use of quantum methods to accelerate or verify zero-knowledge proofs.
The resulting assets would likely differ from today’s in both design and cryptographic assumptions, representing an evolution in protocol architecture enabled by quantum tools
DJ: If quantum computing disruption is inevitable, how should crypto investors and builders start positioning themselves today?
Maeda: Although large-scale quantum computing remains a future risk, the cost of mitigation is lower when addressed pre-emptively. Builders should begin implementing modular cryptographic systems that can accommodate post-quantum primitives without requiring complete protocol redesigns.
Monitoring progress in logical error correction and the appearance of ISEQ systems is essential, as these represent inflection points in capability. Experimentation with post-quantum wallets, signature schemes, and hybrid approaches is advisable.
Investment decisions need not be driven by quantum readiness today, but awareness of cryptographic transition pathways may become increasingly relevant over time. As the quantum threat transitions from theoretical to practical, preparedness will become a competitive differentiator.
