The New Math of Quantum Cryptography

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Hard problems are not usually welcome scenes. But the cryptographers love them. This is because some solid math problems include the protection of modern encryption. Any clever technique to solve them will do most cryptography.

Researchers found several years ago A basically new approach to encryption It lacks this potentially weak space. The method of quantum of the method uses the strange features of physics. However, against the previous quantum encryption schemes, which only work for a few special tasks, the new method can perform many broad tasks. And even if it can work, all the problems at the center of ordinary “classical” cryptography become easily solved.

However, this interesting invention depends on unrealistic assumptions. The result was “more of the proof of the concept,” said Sight butCalifornia is a cryptography researcher at the Simon’s Institute for theory of computing in Berkeley. “This is not a statement about the real world.”

Now, a New paper By two cryptographers, they have set the path of quantum cryptography without those foreign assumptions. “This paper says that if some other assumptions are true, quantum cryptography must be present,” said MA.

Fort in the sky

You can think of modern cryptography as a tower with three essential parts. The first part is the bedrock deep under the tower, which is made by a strong mathematical problem. The tower itself is the second part – you can find specific cryptographic protocols that allows you to send private messages, sign to digital documents, send secret ballots and more.

Of these, to secure daily applications to mathematical bedrock, a foundation made with building blocks that are called One -way functionThe They are responsible for the inherent ashthe of any encryption scheme. “It’s one -way because you can encrypt the messages, but you can’t decrypt them,” said Mark ZhadriNTT is a cryptographer in research.

In the decade of the decade, researchers proved that cryptography, built at the top of one -way functions, will ensure protection for many different functions. However, decades later, they are not yet convinced that Bedrock is strong enough to support it. The problem is that the bedrock is made with special difficult problems – technically known as NP problem – which is defined as defined is easy to check whether the solution to a candidate is correct. (Eg, an NP problem is broken into its main causes: tough for large numbers, but easy to test))

Many of these problems seem to be internally difficult but computer scientists It was not able to proveThe If someone discovers an innovative algorithm to solve strict NP problems quickly, the bedrock will collapse and the entire tower will collapse.

Unfortunately, you can’t just move your tower anywhere else. The Foundation-one-way functions of the tower can only sit on the NP problem bed.

To create a tower on strict problems, cryptographers need a new foundation that is not made with one -way function. It seemed impossible until a few years ago, when researchers realized that quantum could help physics.