One-Sentence Conclusion

Quantum computing can theoretically threaten the cryptographic signatures that Bitcoin and Ethereum rely on, but today's quantum computers are still several orders of magnitude away from being able to actually break them. This is a future risk that requires long-term attention but no panic right now. The community is already researching "quantum-resistant" solutions.

💡 You don't need to take any special action for quantum computing right now, and you certainly don't need to move your coins to a so-called "quantum-resistant wallet" — most of those are scams (see the end of this article).

What Exactly Does Quantum Computing Threaten?

The security of cryptocurrencies mainly relies on two types of math: signature algorithms (to prove "this transaction was sent by me") and hash algorithms (used for mining and addresses). The threat level of quantum computing to these two is completely different:

ComponentAlgorithm UsedQuantum Threat
Transaction SignaturesElliptic Curve Digital Signature Algorithm (ECDSA)High: A future quantum computer using Shor's algorithm could derive a private key from a public key
Mining / HashingSHA-256, etc.Low: Grover's algorithm only provides a "square root" speedup, which can be countered by raising the computational power threshold

So the real core risk is signatures being broken — if an attacker can calculate your private key from your public key, they can move your coins. To understand the relationship between addresses and private keys, first see What is a Cryptocurrency Wallet.

Should You Worry Now? — No

Breaking a Bitcoin signature requires millions of stable, error-corrected logical qubits, while the most advanced quantum computers today have only a few hundred "physical" qubits, with high error rates and an inability to run stably for long periods. The gap between the two is astronomical.

  • Most researchers estimate it will take more than ten years, or even longer, to achieve a "practical break."
  • This progress is gradual and public; it won't happen suddenly one day — the community has ample time to upgrade in advance.
⚠️ Note: No one can accurately predict the timeline. Treat it as a "long-term variable to keep an eye on," not a "disaster that will happen tomorrow."

Which Coins / Addresses Are at Higher Risk?

The key is whether the public key has been exposed. In Bitcoin, your address's public key is only revealed on the blockchain when you spend from that address (initiate a transaction).

  • Higher Risk: Old addresses that have been reused and have had their public keys exposed; early "Pay-to-Public-Key" (P2PK) addresses, like some coins from the Satoshi era.
  • Lower Risk: Modern addresses that have never spent from them and whose public keys are unexposed (the public key is "hidden" by hashing).

Ethereum's account model is different; the address is the hash of the public key, and it's used in every interaction. The ecosystem is also advancing research on post-quantum solutions. For background, see What is Ethereum.

How Is the Crypto Community Responding?

This is a seriously addressed topic, with two main directions:

  • Post-Quantum Cryptography (PQC): Replacing existing signatures with new "quantum-resistant" algorithms. The U.S. NIST has been releasing post-quantum standards since 2024, and wallets and public blockchains will gradually adopt them.
  • Protocol Upgrades: Bitcoin, Ethereum, etc., can all migrate to quantum-resistant signatures via soft/hard forks and guide users to move their coins to new, secure addresses.
💡 When the day for migration truly comes, there will be extensive public warnings and guidance from exchanges and mainstream wallets. Follow the mainstream, and you won't be left behind.

What Should a Regular Beginner Do Now?

  1. Don't Reuse Addresses: Modern wallets (including exchange withdrawals) default to giving a new address each time. This inherently reduces the risk of public key exposure. Just keep this habit.
  2. Use Mainstream Wallets and Exchanges: They will follow post-quantum standard upgrades. You just need to update normally. For choosing a platform, see How to Choose an Exchange.
  3. Master the Basics: Quantum is a "distant worry," while seed phrase leaks, phishing, and fake customer support are "immediate threats." First, solidify your security setup.
  4. Stay Informed, Don't Fuss: No special actions are needed now. Just periodically check on progress.

Beware of "Quantum Panic" Scams

⚠️ Scammers love to exploit panic. Common tactics: ① Falsely claiming "quantum has broken Bitcoin, move your coins to our quantum-resistant wallet now"; ② Tricking you into entering your seed phrase/private key for "quantum hardening"; ③ Selling "quantum-resistant upgrade services" for a fee. Remember the golden rule: Anything asking you to transfer coins or hand over your private key/seed phrase is a scam.

Summary

Quantum computing is a real topic worth long-term attention, but it is not an immediate threat: the machine needed to break things is still far off, and the community is actively preparing quantum-resistant solutions. Beginners just need to maintain good habits, follow mainstream upgrades, and avoid being taken in by panic-driven scams. For systematic tracking of such macro and technical risks, you can visit the sister site Market Pulse Daily for more in-depth analysis.

This article is for educational purposes and does not constitute investment advice.