Quantum Computing

A few days ago I had an old friend reach out to me on LinkedIn. He asked if I knew anything about Quantum Computing among other topics and I had to confess that I didn't really know much. Today I came across it again as it relates to machine learning and so I did a bit more research.

There is a different vocabulary associated with Quantum Computing and that takes a bit of getting used to. With traditional computing you have a bit which represents either the number 0 or the number 1. Quantum computing uses qubits which can be either a 0 or a 1 at the same time. Now string a bunch of bits together and you can represent things like numbers or letters. If you have two numbers you want to add together, you can add their bit representations and you have a single number as the result. With qubits, you add two representations of numbers and have all possible sums for all possible inputs with a single operation. So if you have an 8-bit number, you can count from 0 to 255. Assuming you have space for the results, adding all possible 8-bit numbers results in 512 operations. With Quantum Computing you can get all 512 results in a single operation.

Now start thinking about really large numbers. The larger the numbers, the more operations it takes to come up with all possible outcomes. This idea starts to open up a number of very difficult problems that can now be solved.

If you can do addition on a computer, you can also do multiplication. If you can do that multiplication very quickly then you have something that will help with encryption and decryption of confidential information. Some worry that Quantum Computers can be used to hack into secure banking systems. Fortunately there are secure encryption and decryption techniques using Quantum Computing that are unbreakable and so the moment the technology becomes viable, we will just need to change our current security protocols.

Some scientists believe that Quantum Computing is still a ways off. Others see it as being much closer. The real question is what will the applications be. If we go back 50 years and try to come up with possible uses for traditional computers, we couldn't possible imagine how they are being used today. The same will be true for Quantum Computing and that is what makes it interesting.