Twenty five years ago computer programmers were racing to fix the millennium bug amidst fears that it would cause banking systems to crash and planes to fall out of the sky.
Much to everyone’s relief the impact turned out to be minimal.
Today, some fear there is a new critical threat to the world’s digital infrastructure. But this time, we cannot predict exactly when it will move from theory to reality, while the ubiquity of digital technology means fixing the problem is even more complicated.
That’s because the arrival of quantum computing means that many of the encryption algorithms that underpin and secure our hyperconnected world will be trivially easy to crack.
Quantum computing is radically different to the “classical” computing used today. Instead of processing binary bits which exist in one of two states – one or zero, on or off – quantum computing uses qubits, which can exist in multiple states, or superpositions.
“The reason why it’s so powerful is because you’re doing all those possible computations simultaneously,” Prof Nishanth Sastry, director of research for computer science at the University of Surrey, explains. This means it’s “much, much more efficient, much, much more powerful.”
This means quantum systems offer the possibility of solving key problems that are beyond classical computers, is areas such as medical research and materials science, or cracking particularly complex mathematical problems.
The problem is some of those same mathematical problems underpin the encryption algorithms that help to ensure trust, confidentiality and privacy across today’s computer networks.
Today’s computers would take thousands, even millions of years, to crack current encryption standards, such as RSA. A suitably powerful quantum computer could, theoretically, do the job in minutes.
“Anything that’s protected by something that’s vulnerable becomes fair game for people that have access to quantum relevant computers,”
This has implications for everything from electronic payments and ecommerce to satellite communications. “Anything that’s protected by something that’s vulnerable becomes fair game for people that have access to quantum relevant computers,” says Jon France, chief information security officer at non-profit cybersecurity organization ISC2.
Quantum computers capable of breaking asymmetric encryption are thought to be years away.
But progress is being made.
In December, Google said its new quantum chip incorporates key “breakthroughs” and “paves the way to a useful, large-scale quantum computer”.
Some estimates say a quantum device capable of breaking current encryption would require 10,000 qubits, while others say millions would be needed. Today’s systems have a few hundred at most.
