Quantum communication - resistant to eavesdropping

Here, too, the key lies in pairs of entangled photons. Our protagonists, Alice and Bob, exchange photons from the entangled pairs and measure their polarization directions. The resulting values can then be used as a key for encryption. Alice and Bob can then verify that no one has been eavesdropping on them. They simply need to combine the results of a few measurements and compare them openly, for example, by calling each other.

The results should have been perfectly consistent, because the photons were, after all, intertwined. A spy who measured the polarization of the transmitted photons in any way would have to destroy this perfect match. Any difference, therefore, becomes suspicious—either because it was introduced by a spy or because it results from a disruption in the information transmission channel (e.g., optical fiber). Data transmission protocols based on a similar scheme could revolutionize telecommunications in the future, significantly improving the security and confidentiality of information we transmit, such as personal account numbers or credit card numbers.

It's a long way from transmitting the quantum states of individual particles through space to teleporting the quantum state of an entire person. But the laws of nature don't prohibit the construction of a device capable of achieving this.