The threat for conventional systems from Quantum Computers

I am listing recent developments in the race of developing Quantum Computers :

In 2019 Google told about their 53 quantum bit Quantum Computer Sycamore. It was reported to be
vastly faster than the fastest supercomputers in certain tasks. They claimed to have Quantum Supremacy.

In 2020 IBM told about their operational 65 quantum bit Quantum Computer Hummingbird.

In December 2020 China told about their operational optical Quantum Computer Jiuzhang . It is
supposed to be 10 billion times faster than a fast supercomputer in a certain task. The ”programming” of optical quantum computers is however expected to be much slower than e.g. with Hummingbird.

Recently, in December 2021, IBM told about their 127 quantum bit Quantum Computer Eagle. It has a theoretical potential to be 4 billion billion times faster than the Hummingbird.

Finally, also smaller teams have reported about operational Quantum Computers. The Team related
to the Aalto University in Finland announced in November 2021 about having started a new 5 quantum bit Quantum Computer developed locally. This an equivalent of a 32-bit blazingly fast supercomputer.

CONCLUSION :

Many companies, high-tech countries, and University research groups have advanced quickly in
the art of quantum computing. It is fully possible that several intelligence gathering instances are preparing to crack all and any encryption algorithms now commonly used to encrypt the sent contents and/or to eject hostile commands to critical systems, if needed. It would quite time consuming and expensive to make the keys of the traditional encryption devices significantly longer. The serious countermeasures anticipating very advanced cyber attacks against critical infrastructures using quantum computers must still be started right now. A feasible way is to add Andihce devices to the critical systems.