The Quantum Threat to Bitcoin: How Your Coins Can Be Stolen in Under 9 Minutes

Understanding how quantum computers work is not enough to comprehend the threat they pose to bitcoin. To grasp this, it's essential to know how bitcoin's security is built and where its weaknesses lie. Bitcoin uses elliptic curve cryptography, which relies on a one-way function to ensure that only the owner of a private key can access their coins. However, a quantum algorithm known as Shor's algorithm can break this encryption, potentially allowing an attacker to steal bitcoin. The recent paper by Google's Quantum AI division has reduced the estimated number of qubits required to run Shor's algorithm, making the threat more realistic. The article delves into the details of how Shor's algorithm works and how it can be used to break bitcoin's encryption, as well as the recent developments that have made this threat more pressing. It also explains the concept of a 'mempool attack' and an 'at-rest attack', and how they can be used to steal bitcoin. The article concludes by highlighting the vulnerability of 6.9 million bitcoin that have already been exposed on the blockchain, and sets the stage for the next piece in the series, which will explore the practical implications of this threat and what can be done to mitigate it.