Many people fear the ability of future quantum computers to crack the cryptographic keys on which modern life depends; these protect everything from smartphone banking apps to online payments. Now the US National Institute of Standards and Technology (NIST) has officially approved cryptographic technologies that are considered resistant to attacks from quantum computers. These include an encryption algorithm – used to secure online data – called CRYSTALS-Kyber, along with three algorithms for use in digital signatures that provide identity verification. They all rely on proven mathematical techniques, including one called structured unions.
“We expect these algorithms to be widely adopted around the world,” says Dustin Moody, a mathematician at NIST in Gaithersburg, Maryland.”It’s officially a post-quantum world,” says John Graham-Cumming, chief technology officer at Lisbon-based Internet services company Cloudflare.
Quantum code crackers
Quantum computers process information using quantum phenomena such as superposition — the ability of atomic-sized objects to exist in a combination of multiple states simultaneously. Current quantum machines are still rudimentary, but once they are large enough, they will be able to perform certain tasks exponentially faster than conventional computers. In particular, quantum computers will excel at cracking secret keys for the encryption systems that are most widely used today.
To prepare for a potential privacy apocalypse, cryptologists have been developing algorithms that should be immune to quantum computer attacks. And in 2016, NIST invited computer scientists around the world to submit their best candidates for such “post-quantum” algorithms. The process has now reached a “major milestone”, says Moody, with the first set of four confirmations announced on 5 July.
“Our standardization process has been going on for more than five years and started with 82 proposals that were sent to us,” says Moody, who led the NIST tender process. “After a tremendous amount of evaluation by NIST and the cryptographic community at large, we are excited to announce the first [post-quantum cryptographic] algorithms that we will standardize.”
The algorithms NIST chose have been the subject of far more scrutiny than the cryptographic systems most used during the first two decades of the Internet age, says Bas Westerbaan, a research engineer at Cloudflare Research based in Nijmegen, Netherlands. “So there is trust.NIST will now begin formulating precise specifications for how to implement the algorithms, and expects to release its official standard in 2024 after receiving feedback from the cryptographic community.
Meanwhile, an international organization called the Internet Engineering Task Force (IETF) will consider how to build the algorithms into real applications. “Once this work begins, we can begin to integrate these algorithms into browsers,” says Eric Rescorla, chief technology officer of the Firefox browser team at Mozilla in San Francisco, California. “I would expect to see a test deployment of post-quantum key exchange by 2023, but full deployment may take longer.”
“Cryptographic algorithms are very difficult to implement securely,” adds Rescorla. “We have a lot of experience implementing classical algorithms, but much less experience with post-quantum algorithms, so it’s important that implementers take their time and get it right to protect user security.”Once the testing phase is complete, technology providers will be able to deploy the algorithms during regular software updates, and typical users won’t even realize their devices have entered the post-quantum age.
Source Journal Reference: Davide Castelvecchi, These ‘quantum-proof’ algorithms could safeguard against future cyberattacks, Nature News (2022),https://www.nature.com/articles/d41586-022-01879-6
