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Now, a new paper(opens a new tab) by two cryptographers has laid out a path to quantum cryptography without those outlandish assumptions. “This paper is saying that if certain other conjectures are true, then quantum cryptography must exist,” Ma said.
Castle in the Sky
You can think of modern cryptography as a tower with three essential parts. The first part is the bedrock deep beneath the tower, which is made of hard mathematical problems. The tower itself is the second part — there you can find specific cryptographic protocols that let you send private messages, sign digital documents, cast secret ballots and more.
In between, securing those day-to-day applications to mathematical bedrock, is a foundation made of building blocks called one-way functions. They’re responsible for the asymmetry inherent in any encryption scheme. “It’s one-way because you can encrypt messages, but you can’t decrypt them,” said Mark Zhandry(opens a new tab), a cryptographer at NTT Research. ...
Alas, you won’t be able to use Khurana and Tomer’s new approach to send secret messages any time soon. Despite recent progress, quantum computing technology is not yet mature enough to put their ideas into practice. Meanwhile, other researchers have devised quantum cryptography methods that could be used sooner(opens a new tab), though more work will be needed to establish that they’re truly secure. ...
See the full story here: https://www.quantamagazine.org/quantum-scientists-have-built-a-new-math-of-cryptography-20250725/?utm_source=substack&utm_medium=email