Many science fields like physcis, mechanics and space have reached their quantum level and the knowledges are very common to even a layman. But, have you wondered what is quantum internet and how it works? Let’s say Adam has a message he wants to send to his friend Jack. He encrypts it with a “key” – a sequence of 0s and 1s that unlocks the message. In quantum encryption, he sends this key using one of two intertwined alphabets. An eavesdropper has to guess which alphabet to read. A wrong guess and he’ll be spotted.

Here, our alphabets are shape (a circle means a 0, a triangle a 1) and color (green means 0, orange means 1). Jack reads the shape alphabet – Adam’s message of 1, 0, 0 is encoded as “triangle, circle, circle” – and later confirms that Jack sent the key as shapes.

But if an eavesdropper tries to read the message, half of the time he’ll read the wrong alphabet (a typical key requires thousands of such guesses). When he does, the quirky rules of quantum mechanics dictate that reading one alphabet randomizes the information in the other. When Jack checks with Adam later, he’ll quickly spot the eavesdropper.

Resource: Popular Science