The Quantum Threat to Bitcoin: How a Quantum Computer Can Steal Your Cryptocurrency in Under 10 Minutes

The first part of this series explored the fundamentals of quantum computing, but understanding how it works is only half the story. To grasp the potential threat to bitcoin, it's essential to comprehend what a quantum computer is attacking and where the weaknesses lie. This piece examines bitcoin's encryption, the role of elliptic curve cryptography, and the nine-minute window identified by Google's recent research. Bitcoin's security relies on a one-way map, where a private key is used to generate a public key through a complex mathematical operation. This process is easy to perform in one direction but virtually impossible to reverse using classical computers. However, a quantum algorithm known as Shor's algorithm can efficiently solve the discrete logarithm problem, potentially breaking bitcoin's encryption. The algorithm utilizes the principles of superposition, entanglement, and interference to find the period of a function, which is crucial for determining the private key. Google's paper has reduced the estimated number of qubits required to run Shor's algorithm, making the threat more feasible. The research introduces a practical attack scenario, where a quantum computer can precompute parts of the algorithm and then quickly derive a private key when a target public key appears. This has significant implications for bitcoin's security, particularly for the 6.9 million coins that have already exposed their public keys on the blockchain.