Safeguarding against quantum threats
When Apple integrated cuttingedge security software on iMessage to guard against hackers with quantum computers, it called Douglas Stebila to make sure everything was done right.
Stebila is a University of Waterloo cryptographer who develops postquantum algorithms, or formulas that will repel attacks from quantum computers.
In 2016, the National Institute of Standards and Technology in the U.S. issued a call for proposals to develop quantum-safe algorithms. About 70 researchers submitted proposals that were publicly reviewed.
There was a lot of co-operation among researchers, sharing their results, finding flaws and improving the algorithms. And in 2022, the institute selected four encryption algorithms to form the current standard.
If a product does not meet the NIST standard, the U.S. government will not buy it, so the algorithms are usually adopted by national governments and tech companies, said Stebila.
Apple selected two of the standard algorithms in its latest security upgrade for iMessage, and Stebila and his research team at the University of Waterloo checked the work.
“I analyzed that integration to see if they got things right, and it looks like have a good design there,” said Stebila.
Apple’s use of the quantum-safe algorithms is the largest adoption of this technology so far, he said. Google has experimented with it in Chrome, and the encrypted-messaging platform Signal has also used quantum-safe cryptography, he added.
Based on the small quantum computers available in research labs now, and the theory for bigger quantum computers, the cryptographers have a mathematical model of how the next generation of super computers will behave, said Stebila.
The models enable Stebila to develop quantum-safe algorithms now, years before the first quantum computers are available to the public, which is likely 20-plus years away.
But their awesome potential to crack current encryption has created a spinoff industry in quantumsafe cryptography.
“This is preparing for the quantum era,” said Stebila.
Quantum computers use some of the properties and characteristics of atomic particles like photons, electrons, neurons and the like in addition to the one’s and zero’s of binary code to process information.
There are lots of small quantum computers in research labs, but they are error prone.
But the next generation of supercomputers will do some tasks at unheard of speeds, enabling them to break open RSA encryption which protects most online commerce.
The math behind RSA is based on prime numbers — if you multiply two prime numbers together, that is easy to do, but to factor the result back to the original numbers, that is harder to do, said Stebila.
“We don’t know how to do it efficiently on a normal computer, but we can do it efficiently on a quantum computer,” he said.
“We do have quantum algorithms on paper that would break some of the cryptography we are using today.”
The standards for quantum-safe algorithms will change and evolve as the technology advances. Cryptographers like Stebila are always working on better ones.
“But so far the research community has not come up with new algorithms that break the ones we now call ‘quantum safe,’ ” said Stebila.
But the models say the threats from quantum computers are real, said Stebila, so communications should be secured now, as criminal hackers or hostile states can steal and store huge amounts of encrypted data in the present and open it in the future with a quantum computer.
“Not all of it will be interesting in 30 years, but some of it might be,” said Stebila.