A quantum encryption technique could make it nearly impossible for someone to fake the location of a computer or device.
When sending information from one computer to another, there are times when it would be useful to verify the recipient鈥檚 location. These range from making sure military intelligence gets to the right person to preventing a prankster from ordering pizza to someone else鈥檚 house as a joke. It isn鈥檛 possible to create a fully secure method to verify someone鈥檚 location using classical computers. But now it seems it will be with quantum computers.
at the University of Copenhagen in Denmark and his colleagues have developed a system for verifying location that is immune to hacking attempts by any existing machine. It takes advantage of special properties of the basic units of memory in quantum computers, known as quantum bits, or qubits.
Advertisement
Suppose you wanted to verify the location of a device. With the new system, you would connect it to two quantum computers that would then exchange a combination of quantum and classical information. The data is transmitted in such a way that it would be impossible for a scammer to spoof or copy it without being detected. This is thanks to the fact that information stored on a qubit can鈥檛 be copied surreptitiously.
The team found that exchanging a single qubit and a million classical bits would be enough to make the system secure against anyone with a quantum computer smaller than a million qubits. In other words, tricking the system would require a quantum computer thousands of times larger than any that currently exist.
鈥淎s long as quantum bits are not as available as classical, as long as they are harder to manufacture, then our protocols will be secure,鈥� says Christandl.
at the University of Cambridge says the new protocol should be simple to implement on existing quantum computers as it uses just one qubit. And at the University of Montreal in Canada says the work is the most exciting result in the field in a decade.
Christandl says his team aims to tweak and simplify the approach until it could be run on a device no bigger than a credit card chip.
Nature Physics
