For roughly 30 years, experts in digital cryptography have been monitoring a distant threat: that a powerful enough quantum computer could one day render the most widely used forms of encryption—the layer of code protecting everything from national security secrets to personal banking records—obsolete. Today, the U.S. Commerce Department’s National Institute for Standards and Technology (NIST) is unveiling the final version of three new algorithms, long in development, that are designed to counteract the threat. (The White House will also hold an event to celebrate the new standards.) Hopefully, they're not too late.
Traditional encryption relies on cryptographic algorithms, mathematical equations that must be solved to unlock the data they are encoding. Three of the most widely used cryptographic algorithms in use today—RSA, elliptic curve cryptography and Diffie-Hellman key exchange—rely on the fact that particular kinds of mathematical problems, involving factoring large numbers and finding “discrete logarithms,” are incredibly labor-intensive to solve using a classical computer.
With current technology, cracking the latest RSA standard, for example, could take a billion years or more. But in 1994, mathematician Peter Shor published a groundbreaking paper showing how, with a theoretical quantum computer, you could break all three of these cryptographic schemes in mere hours. It is estimated that 90 percent of internet connections begin by using RSA to establish a secured “handshake,” so the scope of the threat is massive. (Not everything is under direct threat, though: The Advanced Encryption Standard, or AES, a so-called symmetric-key algorithm that’s used to secure highly classified U.S. government data, could potentially be compromised by a different kind of quantum attack than Shor described, but can be secured through a relatively simple change.)
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