While quantum computers are still in their early stages, experts warn they could eventually pose a threat to Bitcoin’s security. Research indicates that approximately 4 million Bitcoins, representing 25% of all coins, are vulnerable to potential quantum attacks. Of particular concern are the earliest Bitcoin addresses, including those believed to belong to Bitcoin’s mysterious creator, Satoshi Nakamoto.
Recent developments in quantum computing have raised eyebrows in the cryptocurrency community. Google’s Willow chip, featuring 105 qubits, demonstrated its power by solving a complex problem in just 5 minutes – a task that would take traditional supercomputers 10 septillion years. However, experts estimate that breaking Bitcoin’s encryption would require about 13 million qubits, far beyond current capabilities. The fixed supply cap of Bitcoin adds another layer of complexity to quantum security concerns.
The threat comes from quantum algorithms like Shor’s Algorithm and Grover’s Algorithm, which could potentially break the cryptographic systems Bitcoin relies on. Scientists calculate that 317 million physical qubits would be needed to break Bitcoin’s ECDSA signature system within an hour. Both the SHA-256 hash function used in mining and the ECDSA signature system could become vulnerable to quantum attacks. Most vulnerable addresses can be protected by transferring to p2pkh addresses that have never been used to spend coins.
Despite these concerns, the timeline for developing quantum computers powerful enough to threaten Bitcoin remains distant. According to physicist Sabine Hossenfelder, practical applications are “about 1 million qubits away.” The most vulnerable Bitcoin addresses are those using the older P2PK format and reused P2PKH addresses. The global consensus process required for implementing quantum-resistant measures could take years to achieve.
The cryptocurrency community isn’t standing idle. Several solutions have been proposed, including a shift to quantum-resistant algorithms, an upgrade from SHA-256 to SHA-512, and the QuBit soft fork proposal introducing post-quantum public keys.
Ethereum creator Vitalik Buterin has suggested using random, one-time-use keys as a potential safeguard.
While the quantum threat to Bitcoin is real, it’s not immediate. The window of opportunity for quantum attacks during transactions is limited, and current quantum computing capabilities remain far from the level needed to breach Bitcoin’s security.
However, the cryptocurrency community continues to work on preventive measures to protect against future quantum threats.
