Cracking using quantum computing

Comment:

What if quantum computing cracks the theory of public key approach?

Follow-up:

Theoretically, based on Peter Shor’s factorization algorithm, a quantum computer can break a public key cryptosystem in very short time. Thus, public key cryptosystem as we are using it now will become completely useless.

The critical problem of the current public key cryptosystem (the “RSA” algorithm) is that it relies on computational intractability. In other words, its security is not mathematically proven.

Security scientists are actively researching on “provable” public key approaches.

Quantum computer

Comment:

What makes a quantum computer impractical?

Follow-up:

For now, the greatest difficulty is in the implementation of a quantum circuit that is stable. In fact, the problems related to accurately and reliably measuring the quantum bits, namely de-coherence and error correction, are still very difficult to solve in practice, even if we assume we can deploy tremendous amount of resources at the construction of a quantum computer.

Still remember the chaotic theory? It is also anticipated that if we cannot tackle the accurate measurement problem effectively, it would be impossible to scale up the size of a quantum circuit without leading to enormous errors.