Quantum computers have been considered a potential challenge to the cryptographic foundations of modern IT systems for years.

"Current assessments indicate that around 6.7 million Bitcoin are held in address formats that could be vulnerable to quantum attacks in the long term."

1. Cryptographic Foundations of Bitcoin

Bitcoin is based on proven cryptographic methods that ensure ownership, transactions, and network security. Two components are central:

• SHA-256 for hashing and proof-of-work

• ECDSA (Elliptic Curve Digital Signature Algorithm) for digital signatures

While SHA-256 is considered robust even against powerful quantum computers, ECDSA is theoretically vulnerable. Using Shor’s algorithm, sufficiently strong quantum computers could derive private keys from public keys.

This means that once a public key is revealed, the underlying security could be compromised in the long term. Currently, however, no known quantum computers are capable of performing such attacks in practice.

2. Which Bitcoin Holdings Are Potentially Affected

Not all Bitcoin are equally exposed. Particularly relevant are holdings where:

• Public keys are already permanently visible

• Older address formats are used

• Addresses have been reused multiple times

A significant portion of these Bitcoin has remained untouched for years. Nevertheless, they are systemically relevant because they influence trust in the long-term security of the network.

3. Possible Reactions from the Bitcoin Community

Bitcoin is designed so that fundamental changes can only be implemented with broad consensus. Accordingly, the topic of quantum resistance is being discussed cautiously. Possible approaches include:

Quantum-Resistant Signature Schemes

New cryptographic methods could complement or eventually replace existing signatures. These rely on algorithms considered secure even against quantum computers.

New Output and Address Formats

Bitcoin users could transfer their holdings to new, quantum-secure formats. Such a transition would occur over several years and run in parallel with existing standards.

Frameworks for Future Upgrades

Proposals under discussion, such as BIP-360, outline potential technical and organizational frameworks for such an upgrade. Implementation would be gradual and voluntary.

4. Potential Impacts on Bitcoin-Only Business Models

For businesses exclusively focused on Bitcoin, the quantum computing debate has several long-term implications:

Technological Preparation

Infrastructure, wallet architecture, and signature processes must be designed to integrate future protocol changes. A clear Bitcoin focus makes this planning significantly easier.

Customer Communication and Education

A potential transition to new address types requires clear communication. Bitcoin-only businesses increasingly act as intermediaries between technical development and practical application.

Operational Security

Transition phases carry risks. Clear processes, conservative implementations, and sufficient lead time are essential to avoid errors.

Strategic Positioning

Businesses that address quantum resistance early strengthen their credibility. Long-term, technological foresight can become a decisive factor in building trust.

5. Quantum Computers as a Long-Term Stress Test

Quantum computers do not pose an immediate threat to Bitcoin. Rather, they serve as a long-term stress test for a system designed for maximum security and minimal attack surfaces.

Bitcoin’s history shows that developments are possible without compromising its core principles. In the context of quantum computing, this evolutionary approach is likely to remain crucial.

6. Conclusion

The development of quantum computing technology does not change the fundamentals of Bitcoin but does impact strategic planning around infrastructure and business models. For Bitcoin-only businesses, the focus should be on preparation rather than alarmism.

Those who understand technological developments, assess them objectively, and integrate them early into their planning position themselves for long-term stability—regardless of when quantum computers will be able to practically leverage their theoretical capabilities.

Quellen:

• Bitcoin Suisse Outlook 2026
  https://www.bitcoinsuisse.com/research/outlook

• Finews: Bitcoin Suisse Outlook – Quantenrisiken und Sicherheits-Upgrades
  https://www.finews.ch/news/finanzplatz/70501-bitcoin-suisse-outlook2026-peter-camenzind-dominic-weibel-btc-stablecoin-krypto-crypto-finanzplatz-schweiz

• Bitcoin Improvement Proposals (BIP-360)
  https://github.com/bitcoin/bips

• NIST: Post-Quantum Cryptography
  https://www.nist.gov/pqcrypto

• Bitcoin Developer Mailing List – Quantum Resistance Diskussionen
  https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev

• Chaincode Labs: Quantum Computing and Bitcoin
  https://chaincode.com/research/

• Andreas M. Antonopoulos – Cryptography & Bitcoin
  https://aantonop.com