Bitcoin will collapse when quantum computers arrive
While Bitcoin's ECDSA signatures are theoretically vulnerable, the threat timeline is uncertain and migration paths exist. Panic is unwarranted, but preparation is prudent.
The Claim
“When quantum computers arrive, Bitcoin will be worthless because all wallets will be vulnerable to theft.”
The Verdict: MIXED
This claim has elements of truth but significantly overstates the risk and ignores important nuances.
What’s True
- ECDSA is quantum-vulnerable - Bitcoin’s signature scheme can be broken by Shor’s algorithm
- Exposed public keys are at risk - Addresses that have spent coins have exposed their public keys
- Quantum supremacy is advancing - Progress in quantum computing is real
What’s Overblown
- Timeline uncertainty - Cryptographically-relevant QC is likely 10-20+ years away
- Migration paths exist - Bitcoin can upgrade its signature scheme
- Not all addresses are exposed - Unused addresses only reveal hashed public keys
The Nuance
Addresses at Risk
Only addresses that have previously spent coins expose their public keys. These are vulnerable to quantum attack.
Protected Addresses
Addresses that have never spent coins only expose the hash of the public key. While technically vulnerable to Grover’s algorithm, the effective security remains high.
Community Response
The Bitcoin development community is aware of this issue. Post-quantum signature schemes like FALCON or SPHINCS+ could be implemented via soft fork.
What Bitcoin Holders Should Do
- Don’t panic sell based on quantum FUD
- Avoid address reuse (good practice anyway)
- Watch for PQC upgrade proposals
- Consider moving to fresh addresses periodically
Verdict: MIXED - The vulnerability is real but the apocalyptic framing is unwarranted.