New math for quantum encryption

The original version to This story Appear Quanta magazine.

Difficult problems are usually not a welcome scene. But the encrypted people love them. This is because some solid mathematics problems support modern encryption safety. Any smart trick to solve will destroy most of the forms of encryption.

Several years ago, researchers found A radical new approach to encryption This lacks this possible potential spot. The approach takes advantage of the strange features of quantum physics. But unlike the previous quantum coding plans, which only work with some special tasks, the new approach can accomplish a wide range of tasks. And it can work even if all the problems in the heart of the normal “classic” encryption are easily solved.

But this amazing discovery depended on unrealistic assumptions. The result said “more than evidence of the concept,” FermeCherry Researcher at the Simons Institute of Computing theory in Berkeley, California. “It is not a statement about the real world.”

Now, a New paper By two encoders, a road was placed to quantum encryption without those strange assumptions. “This paper says that if some of the other guesses are correct, the quantum encryption should be found,” he said.

The castle is in the sky

You can think about modern encryption as a tower with three basic parts. The first part is the deep foundation under the tower, and it is made of solid athletic problems. The tower itself is the second part – you can find specific encryption protocols that allow you to send private messages, signing digital documents, their secret sounds, and more.

Between, securing these daily applications to the sporty foundation, is a basis made of building blocks called Jobs in one direction. They are responsible for the insecurity in any encryption scheme. He said: “It is in one direction because you can encrypt the messages, but you cannot decipher it.” Mark ZandriChevnated in NTT Research.

In the eighties of the last century, the researchers proved that the encryption designed at the top of functions in one direction will ensure safety for many different tasks. But after decades, they are still not sure that the foundation is strong enough to support it. The problem is that the basis made of special difficult problems – known as NP problems – which determines the feature is that it is easy to check whether any candidate solution is correct. (For example, breaking a number to its primary factors is the NP problem: it is difficult to do large numbers, but it is easy to check.)

Many of these problems seem difficult in essence, but computer scientists I could not prove this. If someone discovers an ingenious algorithm to solve the most difficult NP problems, the foundation will collapse, and the entire tower will collapse.

Unfortunately, you can not simply move your sign elsewhere. The basis of the tower-functions in one direction-cannot sit on the basis of NP problems.

To build a tower on more difficult problems, designers will need a new basis that is not made of functions in one direction. This seemed impossible even a few years ago, when the researchers realized that quantum physics could help.