Online data is usually very secure. Assuming everyone is careful with their passwords and other protections, you could imagine that this machine is locked away in a vault so strong that even all the supercomputers in the world working together for 10,000 years couldn’t crack it.
But last month, Google and others published results suggesting a new type of computer, a quantum computer, could open safes with significantly fewer resources than previously thought.
Change is occurring on two fronts. For one thing, big tech companies like IBM and Google are racing to build ever-larger quantum computers. IBM hopes to achieve a real advantage over classical computers in some special cases this year, and to have even more powerful “fault-tolerant” systems by 2029.
Meanwhile, theorists are refining quantum algorithms, and recent research shows that cracking today’s codes may require far fewer resources than previously estimated.
The end result? The day when quantum computers can crack widely used codes, widely dubbed “Q Day,” may be coming sooner than expected.
quantum hardware competition
Quantum computers are built from quantum bits (qubits), which exploit the counterintuitive properties of very small objects to perform calculations in a different, and sometimes much more efficient, way than traditional computers.
For now, the technology is in its early stages, with the main goal being to increase the number of qubits that can be connected to work as a single computer. Larger quantum computers should be much better in some ways than traditional quantum computers. In other words, you will have a “quantum advantage.”
Late last year, IBM announced a 120-qubit chip that it hopes will demonstrate the benefits of quantum for some tasks.
Google also recently announced plans to accelerate the introduction of secure encryption techniques for quantum computers, known as post-quantum cryptography.
In addition to these tech giants, new approaches are also flourishing. PsiQuantum uses light-based qubits and traditional chip manufacturing techniques. Experimental platforms such as the Neutral Atom System have demonstrated control of thousands of qubits in a laboratory environment.
In response, standards bodies and national agencies are setting concrete timelines for transitioning away from common cryptographic systems that are vulnerable to quantum attacks.
In the United States, the National Institute of Standards and Technology (NIST) has proposed a transition away from quantum-vulnerable cryptography, with the transition nearly complete by 2035. In Australia, the Australian Signals Authority has issued similar guidance, urging organizations to start planning now and move to post-quantum cryptography by 2030.
Algorithms speed up lock picking
Hardware is only half the story. Equally important are advances in quantum algorithms, or how quantum computers can be used to attack encryption.
Much interest in developing quantum computers was stimulated by Peter Scholl’s discovery in 1994 of an algorithm that showed how quantum computers could efficiently find the prime factors of very large numbers. This mathematical trick is exactly what is needed to break the common RSA encryption scheme.
For decades, it was thought that quantum computers would need millions of physical qubits to pose a threat to real-world cryptography. This was much larger than the current system, so the threat felt far away.
That image is now changing.
In March 2026, Google’s Quantum AI team published detailed research showing that far fewer resources may be needed to attack another type of encryption that uses a mathematical object called an elliptic curve. This is what is used in systems such as Bitcoin and Ethereum, and research shows how a quantum computer with fewer than 500,000 physical qubits could potentially crack it in minutes.
This is far more than current quantum computers, but about a tenth smaller than previous estimates.
At the same time, a March 2026 preprint from a collaboration between Caltech, Berkeley, and Oratomic explores what might be possible using neutral atomic quantum computers. The researchers estimate that Scholl’s algorithm can be implemented with just 10,000 to 20,000 atomic qubits. In one design they propose, a system with about 26,000 qubits can decrypt Bitcoin in a few days, but more difficult problems, such as an RSA method using a 2048-bit key, would require more time and resources.
Simply put, code breakers are becoming more efficient. Advances in algorithms and design have steadily lowered the bar for quantum attacks, even before large-scale hardware existed.
What now?
So what does this actually mean?
First, there is no impending catastrophe. Today’s codes cannot be broken overnight. But the direction is clear. Each improvement in hardware or algorithms reduces the gap between current capabilities and a useful quantum cracking machine.
Second, viable defenses already exist. NIST has standardized several post-quantum cryptography algorithms that are believed to be resistant to quantum attacks.
Technology companies are starting to deploy these in hybrid mode. For example, Google Chrome and Cloudflare already support post-quantum protection in some protocols and services.
Particular attention should be paid to systems that rely heavily on elliptic curve cryptography, such as cryptocurrencies and many secure communication protocols. Google’s recent efforts clearly highlight the need to move blockchain systems to a post-quantum scheme.
It’s finally the race for the front two horses. Tracking advances in quantum hardware alone is not enough. Advances in algorithms and error correction are equally important, and recent results show that these improvements can significantly reduce estimated attack costs.
Every new headline about reducing the number of qubits or speeding up quantum algorithms should be understood for what it is: another step toward a future where today’s cryptographic assumptions no longer hold.
The only reliable defense is to intentionally and decisively move to quantum-secure encryption.
This article is republished from The Conversation under a Creative Commons license. Read the original article.
