【Blockchain Rhythm】Recently, there has been a lot of talk about the threat of quantum computing to Bitcoin, but these concerns are actually greatly exaggerated. Let’s take a look at what is really happening on the technical level.
First, let's talk about hash functions. Grover's algorithm sounds powerful, but what it actually does is reduce the search space from 2²⁵⁶ to 2¹²⁸ — which sounds impressive, but the problem is that 2¹²⁸ is still an astronomical number and cannot be practically broken.
Next, encryption algorithms. Shor's algorithm can theoretically crack RSA and ECDSA, and that is true. But here’s a key point: most current quantum computers rely on preprocessing or prior knowledge of certain factors to optimize the process, which is not the same as a pure implementation of Shor's algorithm. They are still running a truncated version.
More importantly, to truly crack Bitcoin, which is a real-time network, it would require rapid, repeated execution. If that were actually feasible, then not only Bitcoin but all cryptography would be at risk.