Can quantum computing really crack Bitcoin? Technical details reveal the answer

【Blockchain Rhythm】Recently, there have been many voices warning 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’s 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 universal implementation of pure Shor’s algorithm. They are still running a cut-down version.

More importantly, to actually crack Bitcoin, which is a real-time network, it would require rapid, repeated execution. If that were truly feasible, then not only Bitcoin but all encrypted data would be exposed. At that point, Bitcoin’s own problem would be the smallest concern.

There’s a detail many people overlook — modern cryptography was designed for the future from the very beginning. The risk of quadratic speedup was anticipated and considered decades ago. So every time you see panic or hype about quantum computing, you should know: behind these voices are mostly people who simply don’t understand the technology and are creating anxiety.