# What is the current situation of quantum computers?

Like other research areas of cryptography, quantum computing consists of hidden and open fractions. Apparently, we can't say certain things about governments' capabilities where academical or industrial developments in quantum computers relatively public.

In this context, what is the current developments in quantum computers? Is it serious threat to current cryptographic algorithms in the near future?

• Would you give more details? Why quantum computers can not be competitive in cryptanalysis? Oct 12 '21 at 16:37
• [reposted with update] The title of the question asks for the current situation. That one is easy, at least for what's open: quantum computers are unable to compete with a computer system based on a microprocessor of the 1970's when it comes to cryptanalysis. Taking integer factorization as a benchmark, the highest claim is 21=3x7 using Schorr's algorithm, or a 6-digit integer using algorithms that can't scale (see this, skipping the stunts at start). Things are similar for combinatorial problems.
– fgrieu
Oct 12 '21 at 18:18
• How many Qubits actually built? Or they are making some fun? How many Q-bits are needed. How much time is needed for the Grover's per setup(query); $~2^{64}$ for AES-128? Oct 12 '21 at 18:19