🚨 Quantum Computing Threatens ~25% of Bitcoin
Quantum computing is emerging as a real and escalating threat to Bitcoin. Analysts warn that roughly 25% of all Bitcoins—about 4–6 million BTC—are stored in legacy address types that expose public keys and are therefore vulnerable to cryptographic attacks once quantum computers reach sufficient power
These risky formats include early Pay-to-Public-Key (P2PK) addresses and reused Pay‑to‑Public‑Key‑Hash (P2PKH) addresses, which reveal a public key when used, creating an exploitable opening
Deloitte’s analysis points to about 4 million #BTC in reused-addresses and an additional 2 million in P2PK addresses
For context, this includes coins likely held in long-dormant wallets, possibly owned by early miners or even Satoshi Nakamoto
The threat is grounded in Shor’s algorithm, capable—once powerful quantum computers exist—of deriving private keys from public keys in minutes, effectively undermining ECDSA, the cryptographic backbone of Bitcoin
The so-called “harvest now, decrypt later” strategy is also a growing concern: attackers may be quietly saving blockchain data today, planning to decrypt and exploit it when quantum capabilities advance
Industry Response & Countermeasures
Bitcoin developers propose freezing and migrating vulnerable funds. A recently introduced BIP (Bitcoin Improvement Proposal) proposes a phased approach to freeze coins in vulnerable addresses and transition them to quantum-resistant formats
Post-quantum cryptography is actively under development. Solutions like SPHINCS+, lattice-based systems (e.g., CRYSTALS‑Kyber, Dilithium), and hybrid schemes are being tested—some already on Bitcoin testnets
Specialized firms and protocols are stepping in. Players like Naoris Protocol and Quantinuum are developing infrastructure for quantum-resistant blockchain security and exploring mechanisms to integrate safe cryptography without requiring disruptive forks
💡 The threat of quantum computing to #Bitcoin is real, but solvable