![\"Bearded](\"https:\/\/www.newsbeep.com\/au\/wp-content\/uploads\/2026\/07\/42da6892e8be70bca654c6b8ea7bdc97.jpeg\")
<\/p>\nImagine this.<\/p>\n
You’re catching up on some emails. Verifying your identity with a passport picture. Paying an invoice with your bank details.<\/p>\n
In the background, a “bad actor” is collecting all of your encrypted emails.<\/p>\n
For now, that data is just an indecipherable jumble of letters and numbers.<\/p>\n
But the person harvesting it is patient. They’re waiting for something called “Q-Day” to arrive.\u00a0<\/p>\n
That’s the day a quantum computer will be powerful enough to uncover not only your online data, but classified documents and spy secrets.\u00a0<\/p>\n
“Right now encryption is protecting this data,” Sushmita Ruj, associate professor at the University of New South Wales’ Institute for Cybersecurity, says.<\/p>\n
“But what if a computer comes in later that decrypts everything? It becomes a real catastrophe.”<\/p>\n
And depending on who you ask, Q-Day is right around the corner.\u00a0<\/p>\n
The algorithm that changed everything<\/p>\n
This digital doomsday situation was set in motion in 1994, when a computer scientist called Peter Shor came up with a radical idea.<\/p>\n
Professor Shor gave a talk at the famous Bell Labs in New Jersey on how a quantum computer could solve a maths problem much faster than a regular computer.\u00a0<\/p>\n
Somewhere along the way, his talk got misinterpreted. People started to assume he had solved a much larger maths problem called factoring.\u00a0<\/p>\n
When Professor Shor gave his talk, he hadn’t. But by the time the rumour mill caught up with him a few days later, he had.<\/p>\n
<\/p>\n
Peter Shor came up with a quantum algorithm to find the factors of large numbers. (Supplied: Christopher Harting\/MIT)<\/p>\n
It was a huge deal, but it takes some maths to understand…\u00a0<\/p>\n
Factors are pairs of numbers that divide another number evenly without remainders.\u00a0<\/p>\n
Take the number 77. Its factors are seven and 11.<\/p>\n
You could guess the factors of 77 even without using a calculator.<\/p>\n
Loading…<\/p>\n
But when the number gets big \u2014 potentially thousands of digits long \u2014 it can range from difficult to impossible for even a supercomputer to find its factors.\u00a0<\/p>\n
This is what underpins public-key encryption<\/a>, a pillar of online security.<\/p>\n This method uses “keys” \u00a0\u2014 one public that anyone can use to send information, the other private that only a specific individual can use to decode it.<\/p>\n The fact it’s easy to multiply factors to create a big number, but much harder to break the number down into its factors is what protects these keys.\u00a0<\/p>\n This is what keeps bank transactions, log-in details, messages and sensitive information like health records and government communications secure.\u00a0<\/p>\n “Public-key encryption works because the numbers are enormous,” Henry Everitt, a physicist and chief scientist with the United States Army, says.<\/p>\n “It would take roughly the age of the universe for our current computers to find those factors.”<\/p>\n But Professor Shor discovered a way for a quantum computer to find factors much faster than 13.8 billion years.<\/p>\n This meant that a quantum computer could one day break public-key encryption, and turn cybersecurity on its head.\u00a0<\/p>\n Professor Shor is also a poet, and he wrote a limerick for the layperson to understand:<\/p>\n If computers that you build are quantum,<\/p>\n Then spies of all factions will want ’em.<\/p>\n Our codes will all fail,<\/p>\n And they’ll read our email,<\/p>\n Till we’ve crypto that’s quantum, and daunt ’em.<\/p>\n The shock waves of Professor Shor’s algorithm would be felt by defence departments, spy agencies, cybersecurity and financial institutions around the world.\u00a0<\/p>\n “[It] would bring our financial markets and electronic commerce to a grinding halt,” Dr Everitt says.\u00a0<\/p>\n “That’s how disruptive it would be if a quantum computer was built and we had to throw out public-key encryption.”<\/p>\n A catalyst for quantum computing<\/p>\n Professor Shor’s algorithm was published at the same time Dr Everitt had been organising a small workshop on quantum technology.\u00a0<\/p>\n “We added a second day to the workshop focused on quantum computing and the implications of Shor’s algorithm,” he says.\u00a0<\/p>\n Henry Everitt arranged one of the first workshops to discuss Shor’s algorithm. (Supplied: US Army)<\/p>\n Back then, a quantum computer was just an idea. A theoretical machine that nobody knew how to construct.\u00a0<\/p>\n What resulted from that workshop was a road map to actually build one \u2014 and financial backing from the US Army.<\/p>\n After all, the army and the likes of the National Security Agency (NSA) relied on public-key encryption to keep their data classified.\u00a0<\/p>\n The US Army Research Office held a workshop to discuss the challenges of building a quantum computer.\u00a0 (Supplied: US Army)<\/p>\n Why join the race to build a machine that threatens to topple your own data protection? Well, better to be on the front foot than playing catch-up, Dr Everitt thought.\u00a0<\/p>\n Contest to secure the internet<\/p>\n When Professor Shor’s algorithm came out in 1994, the deadline to Q-Day felt far away. But progress came thick and fast.\u00a0<\/p>\n In 1995, scientists at the US National Institute of Standards and Technology (NIST) built the world’s first quantum logic gate<\/a>, an important building block for a quantum computer.\u00a0<\/p>\n In 1998, the first early quantum computers were realised. In 2001, IBM ran Professor Shor’s algorithm for the first time, factoring the number 15.\u00a0<\/p>\n IBM researchers in the lab during the 2001 factoring experiment. (Supplied: IBM)<\/p>\n By 2016, data security experts at NIST decided it was time to act. Q-Day was getting uncomfortably close.<\/p>\n They launched a competition to replace public-key encryption with new algorithms that could withstand the power of a quantum computer. \u00a0<\/p>\n Dozens of ideas were submitted for consideration, and NIST chose 69 with potential.\u00a0<\/p>\n Then they asked the wider community of cryptographers \u2014 the makers and breakers of computer algorithms \u2014 to go on the attack.<\/p>\n According to Dr Ruj, cryptography and cybersecurity expert, it’s a cut-throat version of peer review.\u00a0<\/p>\n “You put on your attacker’s hat and try to break [the proposed algorithm],” Dr Ruj says.<\/p>\n “It’s playing the devil’s advocate, trying to figure out whether it’s going to be secure. If not, why? Because in the next iteration you can improve on that.”<\/p>\n The algorithms also had to fit into our existing online infrastructure \u2014 if they didn’t, they would slow down the internet.\u00a0<\/p>\n By 2022, NIST had slimmed the algorithms down to three winners. And so far, these algorithms have held up.\u00a0<\/p>\n Our quantum-safe future<\/p>\n In some corners, the transition to these winning, quantum-safe algorithms is already taking place.\u00a0<\/p>\n But there’s still a long way to go before the entire internet, and our institutions, are protected.<\/p>\n As Dr Ruj points out, it’s a “time-consuming, expensive” process, much like building a full-powered quantum computer.<\/p>\n “It’s very hard to say when we might get a cryptographically relevant quantum computer,” Dr Ruj says.\u00a0<\/p>\n “But what I see from the advances that are happening in the quantum space, we need to [transition] very soon.”<\/p>\n It’s unclear when a quantum computer that’s capable of breaking public-key encryption will be built. (Wikimedia Commons: OJB Quantum\/CC BY 4.0<\/a>)<\/p>\n One of the reasons governments are pushing for organisations to transition to quantum-safe systems before a quantum computer is realised is because of “harvest now, decrypt later” attacks.\u00a0<\/p>\n These attacks involve collecting your encrypted data now and cracking it with a quantum computer down the track.\u00a0<\/p>\n How far down the track? The latest Quantum Threat Timeline Report<\/a> estimates that Q-Day is “quite possible” within the next 10 years, and “likely” in the next 15 years.\u00a0<\/p>\n Some experts have described “harvest now, decrypt later” attacks as a present, potentially unavoidable<\/a> risk.\u00a0<\/p>\n How can you protect your data?\u00a0<\/p>\n It’s up to governments, institutions and online platforms to make these changes.\u00a0<\/p>\n The Australian government wants all organisations to have a plan in place to transition to these quantum-safe algorithms by the end of this year<\/a>.<\/p>\n As Dr Ruj points out, this recommendation isn’t binding.\u00a0<\/p>\n “But for places with a lot of data, like financial organisations, universities, healthcare providers or telecom providers, it’s really important they have things in place.”<\/p>\n Last year Reserve Bank governor Michele Bullock said<\/a> she’s confident banks are taking the “scary” threat of quantum computers seriously.\u00a0<\/p>\n You can check out the transition plans of big players including Google<\/a> and Amazon<\/a> online. Microsoft recently announced<\/a> it was moving its deadline to 2029.<\/p>\n Public-key encryption keeps your bank information safe when online shopping. (Getty Images: Gerardo Huitr\u00f3n)<\/p>\n Dr Everitt believes these twin races to build a quantum computer and protect data against quantum attack are coming to a head.\u00a0<\/p>\n But he’s glad it has taken more than 30 years to get to this point.\u00a0<\/p>\n “It has given us time to catch up,” Dr Everitt says.\u00a0<\/p>\n “The people who are frustrated that it’s taken a generation are not the same people who are relieved that it’s taken a generation \u2014 because of the threat that it poses.”<\/p>\n Shor’s algorithm is considered a catalyst for the early development of quantum computers. (Jake Belcher\/MIT)<\/p>\n While the shock of Professor Shor’s algorithm caused major headaches for cybersecurity, according to Dr Everitt, it “motivated” the development of quantum computing.<\/p>\n “There’s clearly will to explore this, or we would have dropped it a long time ago. I hope that the juice is worth the squeeze.”<\/p>\n![\"Smiling](\"https:\/\/www.newsbeep.com\/au\/wp-content\/uploads\/2026\/07\/312bf7fdfc7343e1ab30e3557b7dbfd2.jpeg\")
<\/p>\n![\"The](\"https:\/\/www.newsbeep.com\/au\/wp-content\/uploads\/2026\/07\/00afc7602bcc3e9e91c890756024ecf1.jpeg\")
<\/p>\n![\"Two](\"https:\/\/www.newsbeep.com\/au\/wp-content\/uploads\/2026\/07\/0b20ee84d38e86159ef751627bc6c279.jpeg\")
<\/p>\n![\"A](\"https:\/\/www.newsbeep.com\/au\/wp-content\/uploads\/2026\/07\/d6b7b8fe7e293f3c117d4cfb7563cb9b.jpeg\")
<\/p>\n![\"Woman](\"https:\/\/www.newsbeep.com\/au\/wp-content\/uploads\/2026\/07\/a349eb24cad0a401ed14734fcd39f212.jpeg\")
<\/p>\n![\"A](\"https:\/\/www.newsbeep.com\/au\/wp-content\/uploads\/2026\/07\/1d6d371289060145a27947f70cb19160.jpeg\")
<\/p>\n