Threat of quantum computers to crypto

1. Breaking ECDSA / secp256k1 (used in Bitcoin, Ethereum, etc.) with Shor’s Algorithm.

2. Risk of stealing funds from addresses whose public keys have been exposed.

However, current quantum computers are NOT yet strong enough to break public crypto keys, the real threat is estimated to be 10–20 years away, still under debate.

Can crypto "overcome" this problem?

Yes, technically it is possible. The way:

a. Quantum-resistant cryptography

New quantum-resistant algorithms, for example:

  • Lattice-based (Dilithium, Falcon)

  • Hash-based (SPHINCS+)

  • Multivariate & code-based

    NIST (National Institute of Standards and Technology) has selected post-quantum cryptography (PQC) standards.

b. Upgrade blockchain (hard fork)

Blockchain can:

  • Changing the signature algorithm

  • Adding a hybrid scheme (ECDSA + PQC)

  • Moving funds to a new secure address

    Bitcoin, Ethereum, and major projects can technically be upgraded.

3. Real risks currently


Those at greater risk first:

  • Old Bitcoin address (P2PK) whose public key has been revealed

  • Wallets that reuse addresses multiple times


Those relatively safe:

  • Modern addresses (P2PKH, Bech32)

  • Not revealing the public key until the transaction is made

4. The biggest issue is not technology
Main obstacle:

  • Community consensus (major hard fork)

  • Wallet & node compatibility

  • The size of PQC signatures is much larger