China’s recent advancements in quantum computing, such as the development of “Jiuzhang” and “Zuchongzhi” quantum processors, demonstrate significant progress in quantum supremacy. However, the question of whether these breakthroughs could crack Bitcoin’s cryptographic security is complex and depends on multiple factors.
1. Bitcoin’s Cryptographic Security Relies on ECDSA & SHA-256
Bitcoin uses Elliptic Curve Digital Signature Algorithm (ECDSA) for wallet security and SHA-256 for mining and transaction hashing.
A sufficiently powerful quantum computer could theoretically break ECDSA by solving the elliptic curve discrete logarithm problem (ECDLP) much faster than classical computers.
2. How Many Qubits Are Needed to Crack Bitcoin?
Estimates suggest that breaking ECDSA (secp256k1, used in Bitcoin) would require millions of error-corrected logical qubits.
Current quantum computers (like IBM’s 1,000+ physical qubits or China’s 66-qubit “Zuchongzhi”) are nowhere near this scale.
Error correction and fault tolerance are major hurdles — logical qubits (useful for computation) require thousands of physical…
