I am going to point out I am a Computer Engineer and I presented a project a few years ago (10) on Quantum Computing talking about DWave (the company Google bought). At that time DWave had a 7 or 9 qubit QC.
QC can break private keys. They do this by solving a math problem, product of primes. Example:
3 * 5 = 15
3 and 5 are prime numbers. 15 is the product.
You can see 15 as a “public key”. 3 and 5 as “private keys”.
A QC can, in theory, “test” all numbers and find the prime numbers (5 and 3) just by giving the product of the primes (15).
But there is a huge catch
“In the published article, Google explains how the 53 qubit internally developed quantum computer – Sycamore – was able to perform a calculation in just 200 seconds. Their benchmarks suggest that this would have taken a classic supercomputer around 10,000 years to carry out the same calculation.”
53 qubit is still many orders of magnitude lower than any real application encryption.
I want to point out 53 qubit do not reduce the security of bigger encryption algorithms. A 54 bit encryption is not going to be break in X interations of the 53 qubit. In other words, to break a 54 bit encryption you need a 54 qubit.
To break RSA 1024 you need a 1024 qubit quantum computer which is still pretty difficult to built.
And at this point you cannot just add/chain quantum computers together to form a bigger QCs.
I am guessing we are 15 years from a 512 qubit and 25 years from a 2048 qubit
A 2048 qubit would be pretty dangerous for us right now. But let be honest, in 10 years we might have already changed our encryption to a stronger one.