What is Quantum Computing?
It all sounds super nerdy, and it is. Computers, although in everyone’s hands and homes, due to smartphones and laptops, are still not so easily understood in more technical terms. People own them, but haven’t much of a clue about what goes on under the hood. With quantum computing, even the techies don’t know how they work, such is their complexity.
Fear not, Gossip Lolly is here to the rescue. We’re going to put on our lecturer’s cloak and explain in simple terms what the fuss is all about when it comes to quantum computing.
What’s Quantum Computing in a Single Sentence
Quantum computing is the use of quantum-mechanical phenomena such as superposition and entanglement to perform computation. A quantum computer is used to perform such computation, which can be implemented theoretically or physically.
Thank you, Wikipedia, for that little mouthful.
In other words, it means that quantum computers use quantum mechanics to perform complex calculations, which have advantages over classical computers. This is due to the efficiency of quantum computers.
What’s up with Classical Computers?
Compared to humans computers have certain advantages and can now even think for themselves, even if that thinking is pre-programmed by humans initially. Without getting into the small details, we all know that computers have advantages over mankind.
Computers don’t get bored, they are supremely reliable and amazing at calculation.
What people don’t realise is that they aren’t as good with numbers as you would think.
Traditonal Computers don’t like Exponential Growth
You might have heard the story about the guy who made chess boards for the King? He asked for a grain of rice for every square, but it had to be doubled every day.
That’s a fair price, thought the King.
By the end of the first week it’s only a teaspoon full of rice.
Yes, that is true, thought the craftsman. What his Majesty doesn’t realise is that by the end of the board – all sixty-four pieces – it will be the size of Mount Everest.
That is the power of exponential growth.
Another Exponential Factoid
In case the Mount Everest tale is too long for you. Here’s one that you can use to put your fiance off getting married. Just explain to her that if you have ten people sat on a dinner table, the number of seating possibilities works out at 3.6 million. That is easy enough to stress your Princess the hell out.
How can she possible get it right. Which permutation is going to provide the happiest outcome? Ah never mind – cancel the wedding instead.
How do Exponential Numbers Affect Computing Power?
Just like the poor King, adding an extra digit to a number puts traditional silicon computer chips under more and more pressure. Take this example that I found:
For an eight-character password that has uppercase and lowercase letters and numeric digits, it will take 62\8
attempts. This comes out to be roughly 218 trillion unique combinations. If a classical computer attempts one combination per second, it will take about 218 trillion seconds or 7 million years to crack that password.
If you think that’s a long time…
How About 128-bit AES Ciphers?
Pressuming you had enough silicon to test one-trillion keys per second. Testing all the available unique keys would take, wait for it. 10 million? 100 million? How about 500 billion years? Nah, think again.
It would take 10.79 quintillion years to crack a 128-bit AES cipher. Wowzers. That is 785 times the age of the universe.
Of course that is the worst possible outcome. You could get lucky and crack it in the first million years. 🙂
Regardless, you get the picture. Classical computers don’t like such big numbers. That’s what the premise of our modern-day security relies on. Not that you can’t crack a code, but that the options are so vast it takes far too long to even attempt to crack them.
How do Quantum Computers Perform in Code Cracking?
You’ve guessed it. Much better. Think in the realm of six months or so.
While in isolation six months sounds like a long time, compared to quidrillions of years it’s not even a blink in Father Time’s eye.
Why do Quantum Computers Operate so Efficiently?
First of all we need to backtrack slightly and explain the difference between quantum computers and classical computers. More specifically explain why classical computers are so inefficient relatively speaking.
Computer code, at its simplest, is lots of noughts and ones. It’s as basic as 0001 1001, that type of thing. They’re called bits (4 digits) and bytes (8 digits).
The easier it is for the computer to read the harder it is for a human to read and vice versa. So the easiest human-readable computer language, isn’t a language at all, it’s a drag and drop WYSIWYG – what you see is what you get – interface, such as those you use to make a website.
Think of it like translating from English into French then French into Chinese. The more steps involved the harder it is for the person or in our case the computer.
Quantum Computing Derives its Power from Quantum Mechanics
Instead of those pesky noughts and ones preferred by classical computers, quantum computers are fundamentally different in their approach. Qauntum computers use superposition and entanglement.
Easy to say, not quite so easy to understand, but we’ll give it our best shot. Quantum computers use qubits or quantum bits. A qubit can be in 0, 1 or both at once. This is called superposition. Two qubits can represent four states simultaneously, while 100 qubits can represent 1.3 quadrillion, and quadrillion states simultaneously.
So while classical computers get their power from doing many calculations quickly, it’s a common misconception that qubits work in the same way, but only faster. They are totally different. Qubits do their work simultaneously – they’re in the superposition of many exponential states.
In a nutshell – quantum computers deal with exponential numbers efficiently whereas classical computers struggle exponentially.
This doesn’t mean that classical computers are finished. It just means that like a spanner and hammer, classical and quantum computers are good and bad at different things.
Together classical and quantum computers make for a great partnership. We will always need classical computers, at least you would have to think so; it would be hard to imagine otherwise.
If you have any further questions, don’t be shy, hit us up in the comments below. We’d love to hear your feedback.