Safety First: Understanding Quantum Resistance in Cryptocurrencies, 2026/02/05 10:00:28

The cryptocurrency market is preparing for threats posed by quantum computers capable of overcoming existing cryptographic methods. Various projects are offering their own solutions to these quantum challenges.

What is Quantum Resistance

Quantum resistance, also known as “quantum-safe” or “post-quantum” cryptography, is a field of cryptography focused on creating algorithms that are considered secure against attacks from quantum computers. This primarily concerns public-key cryptographic algorithms, as they are most susceptible to quantum cryptanalysis.

Modern cryptocurrencies rely heavily on such algorithms, which is why they are often cited among the first potential “victims” of quantum computers. Both Bitcoin and Ethereum use the Elliptic Curve Digital Signature Algorithm (ECDSA) to verify transactions. For data hashing, Bitcoin uses SHA-256, while Ethereum uses Keccak-256. Hash functions are generally considered relatively resistant to quantum attacks, whereas the ECDSA algorithm is viewed by many as vulnerable.

In the long term, this implies the need for cryptographic upgrades and a transition to new standards that can maintain the current level of security even with significant advancements in computing technology.

Risk Assessment

Many analysts and researchers believe that the quantum threat to cryptocurrencies is long-term and generally manageable. Experts emphasize that there is no reason for immediate panic, and developers have time to prepare.

Mark Palmer, a researcher at Benchmark, points out that despite the theoretical vulnerability of Bitcoin’s cryptography, real-world attacks may occur “decades from now, not years.” Moreover, even with a sufficiently powerful quantum computer, the threat would only affect coins whose public keys have already been revealed on the blockchain.

Benchmark estimates that potentially vulnerable assets amount to 1-2 million BTC. This concerns funds stored on reused addresses, as well as so-called “Satoshi-era wallets.”

There are also alternative, more pessimistic estimates. Researchers at K33 estimate the volume of vulnerable bitcoins at 6.8 million BTC. Forecasts regarding the timeline for the emergence of a real threat also vary significantly—from 2–5 years to 20–40 years. Well-known cryptographer Adam Back is among those who do not consider the quantum threat relevant in the next couple of decades; he is reluctant to exaggerate the risks and believes that cryptocurrencies will have time to adapt long before its arrival.

Post-Quantum Scenarios for Bitcoin

In the Bitcoin network, the level of vulnerability depends on the type of addresses and their usage patterns. Modern address formats hide the public key behind a hash function until the moment of spending, which reduces the risk of a quantum attack. However, early Pay-to-Public-Key (P2PK) addresses, widely used in the early stages of the network, reveal the public key directly.

This means that such addresses remain potentially vulnerable even if the funds from them have never been moved. Since Bitcoin creator Satoshi Nakamoto and early miners used P2PK addresses, a significant portion of early bitcoin accumulations could theoretically be at risk in the event of the appearance of powerful quantum computers, even if most funds are transferred to quantum-resistant addresses.

Ethereum’s Fundamental Approach

The project’s foundation has officially designated post-quantum security as one of the key development directions and formed a specialized team of developers. Research groups are working on various transition scenarios, including new types of transactions, experiments with rollups, and the use of zero-knowledge wrappers. Researchers have already launched experimental networks for developers and offered rewards for valuable contributions to development.

Cardano — Smooth Adaptation to the Post-Quantum Era

Cardano founder Charles Hoskinson views quantum resistance as one of the key tasks for the long-term development of the network. According to him, progress in quantum computing requires blockchain systems to be adapted in advance to maintain their cryptographic integrity.

In response, Cardano plans to implement an additional security layer called “proof chain,” which will function as an independent layer for verifying the blockchain history. This will involve using Mithril certificates and post-quantum digital signatures designed to protect already confirmed transactions.

Hoskinson notes that such solutions involve trade-offs: post-quantum cryptography requires more data and may reduce network performance, so the transition will be gradual. In the long term, the proof chain is planned to be integrated into the mainnet, gradually replacing elliptic curve cryptography with quantum-resistant alternatives.

Initial elements of this architecture may appear in the coming years, but the full transition to post-quantum security is considered a long-term process that must take into account the community and the ecosystem.

Sui — A General Solution for EdDSA Blockchains

The Sui research team has proposed a cryptographic approach that enhances blockchain resilience against quantum threats without radical changes to the network.

The essence of the solution lies in the fact that in EdDSA (Edwards-curve digital signature algorithm) blockchains, private keys are deterministically derived from the initial seed. This seed can be used in zero-knowledge proofs to confirm account ownership and securely transition to a quantum-resistant scheme without revealing the key itself. Zero-knowledge proofs allow proving knowledge of the seed phrase without showing it to the network, making a secure transition possible even for “sleeping” accounts that have not been used for a long time.

The method is applicable not only to Sui but also to other networks based on EdDSA, such as Solana, Near, and Cosmos, but is not suitable for Bitcoin and Ethereum due to the specifics of their architecture. The main advantage of the solution is backward compatibility. Users can obtain quantum-resistant wallet protection without re-signing transactions, changing addresses, or freezing funds.

Algorand — Partial Protection Already Achieved

Algorand developers currently claim that their blockchain history is protected against quantum attacks. This means that data recorded in the network should remain secure.

However, not the entire Algorand system currently uses quantum-resistant cryptography. For example, the consensus mechanism still relies on classic digital signatures and other cryptographic tools that may be vulnerable to future quantum computers. The project team openly acknowledges this and is working on protection.

As a practical demonstration, Algorand conducted its first post-quantum transaction in September 2025. It was secured using the Falcon algorithm—one of the standards selected by the US National Institute of Standards and Technology (NIST) for post-quantum cryptography.

Winternitz Vault in Solana

Solana’s main step toward quantum resistance remains the Winternitz Vault—a protection mechanism developed by cryptographer Dean Little. It is designed as an additional security layer that enhances the protection of user assets without affecting the basic principles of network operation.

The Winternitz Vault complements Solana’s architecture, allowing assets to be stored in a mode of enhanced protection against potential quantum attacks, without requiring changes to the core blockchain infrastructure.

The vault is based on the Winternitz One-Time Signature (WOTS) scheme, which belongs to the class of post-quantum cryptography. Such signatures are considered resistant to quantum computer attacks and are viewed as an alternative to traditional methods such as RSA and elliptic curve cryptography.

Post-Quantum Startups

Additionally, projects with first-layer blockchains are being created that initially position themselves as quantum-resistant. While most of these projects remain small and their quantum resistance is not yet verified, their very existence indicates that quantum readiness is becoming an important factor in the long-term reputation of blockchain networks.

Conclusion

The quantum threat to cryptocurrencies remains long-term and manageable, but even now, the largest blockchain ecosystems—Bitcoin, Ethereum, Cardano, Algorand, Solana, and Sui—are actively working on post-quantum solutions. This demonstrates that the industry is at least aware of the problem and is preparing infrastructure for the quantum threat in advance.