the quantum threat to crypto just got very, very real and the entire industry is now paying attention.

despite the hardware not being there yet. google’s willow chip runs 105 qubits, ibm heron has 156. but google internally set a 2029 migration deadline.
which chains are actually doing something about it?
- $BTC: Starkware’s CPO dropped the QSB paper Apr 9. quantum-safe transactions today with zero consensus changes. each tx costs $75–200 to execute and can’t use lightning. BIP-360 is in the repo but bitcoin governance moves in years.
- $ETH: Vitalik published the PQ roadmap feb 26. EIP-8141 (frame transactions) introduces hybrid ECDSA + PQ signatures. problem is PQ signatures currently cost ~65x more gas than normal.
- $ALGO: first major chain to run an actual post-quantum transaction on mainnet (nov 2025). google cited them 32 times as the model to follow. the cryptographer who helped build the standard literally works there.
- $ZEC: already private against quantum attacks. shielded ZEC transactions are already quantum-resistant for privacy. what’s left is preventing counterfeiting, which gets addressed by the tachyon upgrade.
- $XRP: PQ upgrade already live on testnet. only 0.03% of XRP supply has exposed keys. also one of the few chains where devs can upgrade security without moving funds.
- $BCH: quantum-resistant vaults shipping may 15. no protocol changes needed, just opt-in smart contracts. uses only sha-256 which is the most trusted assumption in crypto.
- $SOL: quantum-safe signatures made solana run ~90% slower in testnet. for a chain where speed is the entire pitch, that’s a real problem. no solution yet. wallet-level patches exist but the core issue is unsolved.
- $QRL: been running quantum-safe since 2018. 7 years of live production, zero vulnerabilities found in audits.
some chains already shipping PQ stuff in production. others still debating governance proposals that’ll take years to land.
bitcoin and ethereum hold 68% of total crypto market cap and are the most quantum-exposed.
the most quantum-ready chains are the smallest ones. the narrative is still early and probably sticks around for years.