Quantum Computing Explained – And Which Cryptos Are Safe From It

Quantum computing is no longer just a science fiction concept — it’s a rapidly advancing technology with serious implications for cryptocurrencies. While today’s blockchains rely on cryptography that’s safe against classical computers, quantum machines could break much of it in the future.

This article explains what quantum computing is in simple terms, how it affects crypto security, and which tokens are already designed to resist quantum attacks.

What is quantum computing?

Traditional computers use bits, which can be either a 0 or 1. Quantum computers use qubits, which can be both 0 and 1 at the same time thanks to a property called superposition. They can also be entangled, meaning the state of one qubit depends on another. These properties allow quantum computers to solve certain complex problems much faster than today’s best supercomputers.

For example, they can factor large numbers and solve discrete logarithm problems — tasks that would take classical computers thousands of years — using algorithms like Shor’s algorithm. This creates a problem for most cryptocurrencies because their security depends on those exact mathematical assumptions.

Why quantum computing matters to crypto

Most blockchains use public-key cryptography to create wallet addresses and verify transactions. For Bitcoin and Ethereum, this means using the Elliptic Curve Digital Signature Algorithm (ECDSA). It’s secure today because it’s mathematically hard to reverse-engineer a private key from a public one using classical computers.

Quantum computers change that. A sufficiently advanced quantum computer running Shor’s algorithm could derive private keys from public keys in a matter of seconds. This means an attacker could forge digital signatures, steal funds, and impersonate wallet owners.

Even hash functions, such as SHA-256 used in Bitcoin mining, are weakened by Grover’s algorithm, which effectively cuts the strength of the hash in half. While still relatively secure, it would no longer be considered unbreakable.

What is post-quantum cryptography?

Post-quantum cryptography (PQC) refers to cryptographic systems that are believed to be secure even against quantum attacks. Unlike ECDSA, these algorithms are based on problems that are still hard for quantum computers to solve. Common types include:

• Hash-based cryptography: Uses one-way hash functions (e.g., XMSS, WOTS+).
• Lattice-based cryptography: Based on hard problems in high-dimensional lattices (e.g., CRYSTALS-Dilithium, Kyber).
• Code-based and multivariate cryptography: Less common, but used in some theoretical models.

Some projects have already integrated PQC into their core blockchain infrastructure. These are the crypto tokens currently considered quantum-resistant.

Crypto tokens safe from quantum attacks

Solana (SOL)

• Cryptography used: Winternitz One-Time Signatures (WOTS), a hash-based signature scheme.
• How it works: Solana introduced the Winternitz Vault, an optional feature that employs WOTS to generate a new key pair for each transaction. This approach enhances security by minimizing the risk associated with key reuse. The vault uses a truncated Keccak256 hash, offering 224-bit preimage resistance and 112-bit quantum security for collision resistance.
• What makes it different: Unlike Bitcoin and Ethereum, which expose public keys during transactions, Solana’s Winternitz Vault ensures that each transaction uses a unique key pair, reducing the risk of quantum attacks. However, it’s important to note that this feature is optional; users must actively choose to utilize the Winternitz Vault to benefit from its quantum-resistant properties.
• Current status: Launched in January 2025, the Winternitz Vault is available for users seeking enhanced security against potential quantum threats. While it’s not a network-wide default, it represents a proactive step by Solana in addressing future cryptographic challenges.

Quantum resistant ledger (QRL)

• Cryptography used: XMSS (eXtended Merkle Signature Scheme)
• How it works: QRL uses one-time hash-based keys arranged in a Merkle tree. Each transaction uses a unique key, reducing the risk of replay attacks or key reuse. XMSS is NIST-approved and considered secure against quantum attacks.
• What makes it different: Unlike Bitcoin and Ethereum, which expose public keys during a transaction, QRL never reuses keys and doesn’t rely on elliptic curves.
• Current status: Launched in 2018, QRL is one of the earliest post-quantum coins. While adoption remains small, its purpose is long-term secure storage rather than day-to-day payments.

Mochimo (MCM)

• Cryptography used: WOTS+ (Winternitz One-Time Signature Plus)
• How it works: Each transaction in Mochimo uses a new one-time signature that’s immune to quantum decryption. The chain also prunes old blocks to keep size minimal.
• What makes it different: Like QRL, Mochimo avoids key reuse. It focuses on lightweight and scalable infrastructure with strong quantum protection built-in.
• Current status: Also launched in 2018. Market cap remains low and adoption is minimal, but it demonstrates a working hash-based quantum-resistant blockchain.

QANplatform (QANX)

• Cryptography used: CRYSTALS-Dilithium (lattice-based)
• How it works: QANplatform uses lattice cryptography, recently selected by NIST as a post-quantum standard. It supports smart contracts and multiple programming languages.
• What makes it different: Unlike QRL or Mochimo, QAN is positioned for enterprise adoption. It supports cloud deployment in minutes and has built-in post-quantum developer tools.
• Current status: The testnet is live, and the QANX token trades on public exchanges. QAN has partnered with IBM and joined the Linux Foundation’s post-quantum alliance.

What about Bitcoin and Ethereum?

Bitcoin and Ethereum do not currently have post-quantum protection. Both rely on ECDSA, which is vulnerable to quantum attacks. If a quantum computer becomes powerful enough, any previously used address could be targeted. Ethereum developers are exploring upgrades to more secure schemes, but these haven’t been implemented yet.

Vitalik Buterin has acknowledged the threat, stating that “quantum computers break existing elliptic curve signatures” and that Ethereum may adopt alternatives like hash-based or lattice-based signatures in the future.

Key takeaways

• Quantum computing can break existing crypto: Shor’s algorithm could make today’s cryptography obsolete. Public keys could be reverse-engineered into private keys, leading to loss of funds.
• Post-quantum cryptography exists today: Hash-based and lattice-based algorithms provide a strong defense. XMSS and CRYSTALS-Dilithium are already NIST-approved.
• Quantum-resistant tokens are real: Projects like QRL, Mochimo, QANplatform, and HyperCash have already implemented quantum-safe cryptography.
• Most major blockchains are still vulnerable: Bitcoin and Ethereum haven’t upgraded yet, although discussions around future migration are ongoing.

Final thoughts

Quantum computing is not a theoretical threat — it’s a technological race. While a large-scale quantum computer may still be years away, crypto users should start paying attention. A small set of projects have already taken the lead by building quantum-resistant blockchains. For those thinking long-term about crypto security, exploring these tokens is a proactive way to prepare for the next era of computing.

1. 01.

   Should I invest in quantum-resistant crypto tokens?

   

   Quantum-resistant tokens are still a niche area and often have limited adoption. However, they may offer long-term security advantages. Whether or not to invest depends on your risk tolerance and investment goals.

2. 02.

   Is Solana quantum-resistant?

   

   Solana recently introduced an optional feature called the Winternitz Vault, which uses a hash-based signature scheme to provide quantum resistance. However, users must enable this feature manually — it is not the default for all wallets or transactions.

3. 03.

   Is Bitcoin quantum-resistant?

   

   No, Bitcoin is not currently quantum-resistant. It uses elliptic curve cryptography, which is vulnerable to quantum attacks. If Bitcoin is not upgraded in the future, it could become insecure once quantum computers are powerful enough.

4. 04.

   How does quantum computing affect crypto?

   

   Quantum computers can break the cryptography used by most cryptocurrencies, such as Bitcoin and Ethereum. If a powerful enough quantum computer is built, it could reverse-engineer private keys from public keys and steal funds or forge transactions.

5. 05.

   What is quantum computing in simple terms?

   

   Quantum computing is a new type of computing that uses quantum bits (qubits) instead of regular bits. Unlike traditional bits that are either 0 or 1, qubits can be both at the same time, allowing quantum computers to solve complex problems much faster than classical computers.