How can digital assets be defended against quantum computing?

October 31st How can digital assets be defended against quantum computing?

Quantum computing could pose a long-term potential threat to digital assets, as sufficiently advanced quantum machines could break the cryptographic systems that protect many blockchains, especially those that use elliptic curve signatures. Although current quantum hardware is not powerful enough to carry out such attacks, researchers predict that large-scale, fault-tolerant quantum computers could emerge from the mid-2030s onwards, at which point vulnerable public keys and reused wallet addresses could be compromised. Some digital assets are more at risk than others depending on how keys are stored and exposed, but networks with flexible governance and upgrade paths are better positioned to transition to post-quantum cryptography. Work to develop and standardize quantum-resistant algorithms is already underway, and many ecosystems are exploring gradual migration strategies to mitigate risks before quantum computing becomes a practical threat.

What risks do digital assets face from quantum computing?

Quantum computing poses potential long-term risks to digital assets, as many cryptocurrencies rely on cryptographic algorithms that can be weakened or broken by sufficiently powerful quantum machines. Most blockchains, including Bitcoin and Ethereum, use the Elliptic Curve Digital Signature Algorithm (ECDSA) to secure transaction signatures. A large quantum computer capable of running Scholl’s algorithm could theoretically derive a private key from its corresponding public key, allowing an attacker to impersonate a user and drain the funds. Similarly, the hash-based security assumptions used in mining and addressing can be challenged through Grover’s algorithm, which can speed up brute force searches. However, such attacks require quantum computers that far exceed today’s very limited prototypes in terms of qubit count, error correction, and reliability.

Current estimates suggest that quantum computing will not pose a significant threat to major cryptocurrencies for at least a decade, and perhaps longer. Reliable predictions vary, with some experts predicting meaningful cryptographic threat levels around the mid-2030s, while others believe it could take decades for fault-tolerant quantum machines to reach the scale needed to crack elliptic curve keys in real time. The challenge is not just to build more qubits, but to achieve low-error, stable systems in which millions of physical qubits can be combined to form thousands of “logical” qubits capable of sustained computation. Quantum hardware is currently in a noisy intermediate stage, suitable for research but unable to carry out attacks against global financial networks.

Different types of digital assets have different levels of exposure. Funds held in a blockchain address that has never broadcast its public key, such as a modern Bitcoin wallet, are less likely to be immediately vulnerable because only the hashed public key is visible on-chain. The greater risk lies in reused or exposed public keys, stale accounts, and traditional multi-signature setups. Smart contract platforms and DeFi applications also rely on signature verification across a large number of keys, and the rapid advancement of quantum capabilities will create a broader attack surface. Tokens whose core infrastructure relies on upgradable governance may be well-suited for migration, while immutable networks with slow adjustment processes may face challenges adapting in time.

Several mitigation strategies are already underway. Many post-quantum cryptographic algorithms are based on lattice-based or hash-based schemes and are being standardized through global bodies such as the U.S. Department of Commerce’s National Institute of Standards and Technology (NIST). Some blockchain projects are integrating or testing post-quantum signature schemes, and developers of Bitcoin, Ethereum, and other networks are evaluating migration paths that maintain security without disrupting users. Certain assets are already better insulated, especially those using hash-based signature schemes or systems designed with quantum resilience in mind from the start. The migration is expected to occur in stages, with multi-layer migration options such as optional quantum-secure addresses to allow users to move funds before large-scale quantum threats materialize. In summary, quantum computing is a legitimate long-term risk, but not an immediate one, and active research and planning will reduce the likelihood of sudden or unmanageable disruption.

What are the criteria for making a digital asset “quantum resistant”?

A digital asset is considered “quantum-proof” if the cryptographic primitives that protect it remain secure even in the presence of large-scale, fault-tolerant quantum computers. Currently, most blockchain systems rely on elliptic curve or RSA-based public key cryptography, which could be broken by Scholl’s algorithm once quantum machines become powerful enough. To be resilient, digital assets should instead use signature schemes and key exchange mechanisms that rely on mathematical problems considered difficult for both classical and quantum computing. This typically means moving away from number-theoretic assumptions and toward alternatives such as lattice-based, hash-based, multivariate cryptography, or code-based encryption. In other words, quantum resistance depends on the cryptographic algorithms implemented internally, not on how the assets are used.

The second key criterion concerns how public keys and signatures are published. In many blockchains, including Bitcoin and Ethereum, a user’s public key is only revealed when they spend funds. Until then, only the hash of the key is visible. Although quantum speedups may reduce the safety margin, Grover’s algorithm still requires a brute force effort to undo the hash, so this provides a type of delay protection. A true quantum-proof asset avoids exposing public keys in vulnerable forms or relying on signature schemes where knowledge of the public key does not provide a viable attack vector, even for quantum resources. In practice, this means evaluating not only the signing primitives, but also how keys are broadcast, stored, and reused within the transaction flow.

The governance and upgrade path of digital assets will also determine whether they can become quantum resistant in time. Even if an asset currently relies on cryptography that is vulnerable to quantum attacks, it can be considered “future-proof” if the network has clear and coordinated mechanisms for rotating keys, migrating addresses, or moving to post-quantum signature schemes before an actual quantum attack emerges. Networks with flexible scripting environments or robust community-driven governance (such as decentralized autonomous organizations) have clear routes to migration. Conversely, networks that are very rigid, lack upgrade frameworks, or rely on user coordination across millions of wallets (such as Bitcoin’s consensus model) may find it more difficult to adapt before risks become apparent.

True quantum resilience also requires consideration of performance, decentralization, and operational tradeoffs. Some post-quantum schemes generate very large signatures or require large amounts of computation, which may not work on high-throughput blockchains or low-power devices. Quantum-resistant digital assets must therefore balance strong theoretical security with practical ease of use and network efficiency. The goal is to employ cryptography that is secure against quantum attackers without sacrificing decentralization, accessibility, or transaction scalability. Quantum resistance is not a single feature, but a combination of mathematically robust primitives, careful protocol design, flexible upgrade capacity, and real-world performance compatibility.

How can digital assets mitigate potential quantum attacks?

Mitigating the risk of future quantum attacks starts by planning the transition to encryption well before large-scale quantum computers are available. Therefore, the first step is to assess where and how cryptographic assumptions are used throughout the protocol: key generation, signature schemes, hashes, address formats, and network messaging. By performing this type of mapping, developers and ecosystem contributors can identify the most vulnerable components and prioritize which cryptographic primitives should be migrated to post-quantum alternatives such as lattice-based or hash-based schemes.

A second path to mitigation involves exposing public keys as little as possible. In many existing systems, the public key remains hidden behind a hashed address until the user spends the funds. Encouraging best practices such as “single-use” addresses, preventing address reuse, and designing wallets to automate key rotation can create a buffer period during which even a quantum attacker cannot easily retrieve the private key from the exposed public key. While this does not make the network quantum-proof, it increases the margin of safety and reduces the number of assets that are immediately vulnerable during the transition period.

Another important element is the development and testing of hybrid cryptographic schemes that combine classical and post-quantum signatures. Hybrid signatures allow transactions to be verified using both traditional elliptic curve systems and quantum-proof algorithms simultaneously. This ensures backward compatibility, maintains interoperability with existing infrastructure, and allows the network to gradually introduce new cryptography without requiring an immediate consensus-level fork. Research on hybrid approaches and standardization efforts led by organizations such as NIST will help establish a common framework that digital asset networks can adopt in a coordinated and orderly manner.

Meaningful mitigation requires social and governance provisions in addition to technical solutions. Digital assets should establish upgrade pathways through governance mechanisms, protocol improvement proposals, and wallet-level migration plans to support a coordinated transition to new cryptographic standards as needed. This includes educating users, exchanges, custody providers, and node operators about the risks and steps required for secure key migration. The timeline for quantum threat maturity is uncertain, but if you prepare in advance, emergency changes are less likely to be made on short notice. A combination of early cryptographic research, careful key disclosure practices, adoption of hybrid signatures, and strong upgrade governance can position the digital asset ecosystem to securely transition into a post-quantum future.