What is quantum computing?

[capslfern]

TL;DR Summary

what is quantum computing and why is it different from conventional computing? what can it be used for?

I've heard that quantum computing is faster than conventional computing and can break almost all of our security, but how?
What could quantum computing be used for?
What can conventional computers do that quantum cant?
What can quantum computers do that conventional cant?

 

[berkeman]

What reading have you been doing on these questions? It's best if you do some reading on your own and then post links to your reading and ask questions about the parts you do not yet understand.

 

[jedishrfu]

Yes I concur wth @berkeman. Find some articles on quantum computing.

One thing to search for is Shor’s algorithm which will answer your security questions.

Many of our secure systems use RSA encryption which relies on the difficulty of factoring really large numbers of anywhere from 300 to 1200 digits into prime components. The numbers are based on the product of two large primes.

Quantum computers hold the promise of factoring RSA keys into their two primes breaking its security feature as either prime can be used to decrypt the message.

So far, IBM has successfully factored a rather small key into its two primes of 3 and 5 and claimed quantum supremacy.

Jedi