Quantum Computers: Can They Crack Bitcoin's Code?

What is Quantum Technology?

Quantum technology harnesses the principles of quantum mechanics to process vast amounts of data and tackle complex problems much faster than traditional computers. Originating in the early 1900s, it now powers technologies like transistors, lasers, and MRI machines.

Quantum computers, potentially 300,000 times faster than current systems, raise concerns about Bitcoin's security. Google's Willow quantum chip, for instance, significantly reduces computation times, potentially enabling hackers to unlock the algorithms safeguarding Bitcoin and other cryptocurrencies.

Quantum computers could threaten Bitcoin’s cryptographic systems, including the Elliptic Curve Digital Signature Algorithm (ECDSA). However, experts like Adam Back and Michael Saylor believe that the quantum threat to Bitcoin is not imminent, as advanced quantum hardware is still years, if not decades, away.

While research and development are rapidly advancing, Bitcoin is not yet fully quantum-safe. Developers are actively working on upgrades to protect the network from potential quantum risks.

It’s crucial to acknowledge the potential risks, but it is important to note that they are not immediate threats.

How Quantum Tech Could Break Bitcoin Wallets

Quantum computing's primary threat to Bitcoin lies in its potential to compromise the cryptography protecting the network. By exploiting vulnerabilities in asymmetric cryptography, particularly ECDSA, quantum computers could potentially break Bitcoin wallets.

Bitcoin wallets are secured using ECDSA to generate private-public key pairs. The security of this system relies on the difficulty of solving the elliptic curve discrete logarithm problem (ECDLP), which is practically impossible for classical computers.

The real concern is the potential for quantum computers to crack Bitcoin private keys. The 1994 Shor algorithm can potentially break the security of asymmetric cryptography algorithms. While deriving a private key from a public key would require significant time and resources with existing algorithms, Shor's algorithm could accelerate this process substantially.

With the Shor algorithm, malicious actors with access to powerful quantum computers could generate private keys from public keys and forge digital signatures for transactions.

Bitcoin and Quantum Security Risk

Quantum tech could compromise Bitcoin wallets by revealing their private keys, especially for older addresses or those with reused public keys. As quantum computers evolve, the risk of reverse-engineering private keys from exposed public keys grows.

Although quantum computers are supposedly decades away from breaking ECDSA, Bitcoin users should be aware of best practices to mitigate future quantum threats.

Can Quantum Computers Recover Lost Bitcoin?

Analysts estimate that 2.3 million to 3.7 million Bitcoin is permanently lost, representing 11%-18% of the total supply. The question arises: what happens when quantum recovery technologies revive these dormant wallets?

If a quantum computer were to crack Satoshi Nakamoto's wallet, estimated to hold 1 million BTC, and release those coins into circulation, it could trigger significant market volatility.

Quantum computers may unlock lost Bitcoin by cracking the cryptographic keys of wallets with lost or inaccessible private keys. Older Bitcoin addresses, using pay-to-public-key (P2PK) formats that have not been upgraded or reused, are particularly vulnerable. The advancement of quantum computing could exploit these vulnerabilities, potentially unlocking dormant wallets.

In May 2025, BlackRock acknowledged in its iShares Bitcoin Trust (IBIT) filing that quantum computing poses a significant risk to Bitcoin's long-term security due to its ability to break current cryptographic defenses.

Ethical and Economic Implications

Recovering lost Bitcoin raises ethical and economic questions. Reintroducing these coins into circulation could disrupt Bitcoin's scarcity and impact its market value. Some experts suggest burning these coins to protect the network, while others propose redistribution for wealth balance.

Protecting Your Bitcoin from Quantum Threats

Regardless of quantum threats, protecting your Bitcoin requires ongoing vigilance. Fraud, including phishing scams like the zero-value transfer, remains a constant threat.

Approximately 25% of all Bitcoin is stored in addresses that use pay-to-public-key (P2PK) or reused pay-to-public-key-hash (P2PKH) methods, exposing public keys and increasing vulnerability to quantum attacks.

Minimize public key exposure by avoiding address reuse. Use platforms that automatically change addresses with each transaction. Generate new addresses for each transaction, and use wallets that support Taproot and SegWit for enhanced security. Always double-check addresses when sending transactions.

Address poisoning, another common phishing technique, can lead to users copying incorrect addresses when executing transactions.

Bitcoin’s Quantum Resistance: Ongoing Research

Bitcoin's decentralized and open-source nature allows for adaptability, and ongoing research into quantum-resistant Bitcoin wallets suggests that coins face no immediate threat.

Users should follow best practices, such as avoiding address reuse, until quantum-proof cryptocurrencies and wallets are available.

Initial measures to protect Bitcoin include the quantum-resistant asset mapping protocol (QRAMP), proposed by Bitcoin developer Agustin Cruz, which aims to protect Bitcoin from quantum risks while enabling cross-chain functionality without compromising custody or supply limits.

Experts are also developing quantum-resistant cryptographic techniques that could improve scalability, create unhackable wallets, and strengthen cryptography, helping Bitcoin remain resilient in a quantum world.