Quantum Computing: The Looming Threat to Bitcoin’s Survival?

Quantum computers could crack Bitcoin's code—and Wall Street's already placing bets.

Here's why the crypto world is sweating bullets.

The existential risk hiding in qubits

While hedge funds drool over quantum arbitrage opportunities, Bitcoin's SHA-256 encryption suddenly looks like a sitting duck. Early research suggests a sufficiently powerful quantum machine might reverse-engineer private keys from public addresses—turning hodling into a hacker's paradise.

The race against the quantum clock

Core devs are quietly testing quantum-resistant signatures, but progress moves at blockchain speed. Meanwhile, DARPA just funded three post-quantum cryptography startups. Coincidence? (Spoiler: no.)

Sleep tight, crypto bros

Until then? Keep those cold wallets colder—and maybe don't mention this to your Bitcoin-maximalist uncle at Thanksgiving. After all, nothing says 'digital gold' like a vulnerability that could evaporate $1T market cap before Goldman Sachs finishes its morning coffee.

Bitcoin wallets remain secure against quantum computing

Bitcoin uses the cryptographic hash function SHA-256 to secure transactions and generate new blocks by solving complex mathematical puzzles. Many other systems-such as SSL certificates and secure data storage-also rely on this function for encryption. Quantum computers could threaten the security of SHA-256 by breaking the underlying cryptographic algorithms. This WOULD allow a quantum computer to crack the private key of a Bitcoin address. Satoshi Nakamoto’s wallet, holding over one million Bitcoin (worth 105 billion USD at today’s price), would be a prime target.

On the one hand, current quantum computers are nowhere NEAR powerful enough to break Bitcoin’s encryption. The computing power of this technology is measured in quantum bits, or “qubits.” Estimates suggest that over 13 million qubits would be required to pose a threat to Bitcoin wallets. For comparison, Google’s Willow chip achieves fewer than 105 qubits. Furthermore, Bitcoin can defend itself by transitioning the blockchain to quantum-resistant cryptographic algorithms. Researchers have already developed such methods.

Threat to Bitcoin mining

Quantum computers would pose a threat to mining if they could solve proof-of-work puzzles exponentially faster than classical miners. This could lead to a 51% attack, in which a single entity controls the majority of mining power. In such a scenario, the quantum computer could change the network’s rules and enrich itself.

Although powerful quantum computers could theoretically solve the puzzles much faster than traditional machines, several factors mitigate this threat. First, quantum computing performance is expected to improve gradually due to the technical challenges of scaling up qubit counts and implementing robust error correction.

As the first quantum computers enter the market, the impact of any new machine will be diluted. Every quantum computer that joins mining increases overall competition and computational demand. In addition, today’s quantum computers only run for a few seconds. Extending this runtime requires advanced error correction techniques and millions more qubits. This limits the immediate threat to Bitcoin-at least until quantum-resistant mechanisms are implemented.

Malicious actors have other targets

Attackers with access to a quantum computer are likely to target systems with more immediate value long before attacking SHA-256 blockchains like Bitcoin-such as the far simpler cracking of RSA encryption. RSA is used in secure communication, banking, and government data. Anyone storing their wealth in a bank instead of Bitcoin is also at risk from quantum computers.

Malicious actors could also exploit vulnerabilities in critical infrastructure or steal sensitive corporate information. These targets are far more likely to be prioritized due to their broader economic and strategic implications than Bitcoin. Nevertheless, raising awareness within the blockchain community remains important. Transitioning to quantum-resistant algorithms is theoretically easy to implement, but it requires a clear consensus. If that consensus is reached too late, short-term complications could arise.