New quantum computer could mean trouble for encryption

The FBI and the Justice Department might still be at an impasse with Apple, but technology could give it the break it needs in a distant future. In a paper published in the Journal Science, researchers from MIT and Austria's University of Innsbruck have revealed that they were able to not only design but also build a quantum computer that only needs five atoms to factor the number 15. But equally important is the claim that the design is completely scalable, allowing for the addition of more atoms to factor numbers of much larger magnitudes.

Unlike conventional computing that uses bits that can only be either 1 or 2, quantum computing relies on "qubits" that can hold both values at the same time, allowing them to carry out two separate calculations in parallel. At least, that's the idea on paper. Some would contest the actual performance advantages of current quantum computers, like those in Google's labs. The benefits of quantum computing, however, is tied to its scalability.

The laws of physics would inevitably limit how much power you can give a conventional computer, but quantum computing works at the molecular level, which opens up more possibilities. The problem is that such computers aren't the most scalable computers around. Throwing in more atoms actually had the opposite effect and made the system more difficult to control. This is the significance of the research done by MIT professor Isaac Chuang and his team. They used ion traps to hold the five atoms and keep them stable. Furthermore, one of the five atoms is used for storing, forwarding, extracting, and recycling the results done by the other four, reducing the need for more qubits per operation.

While a sample quantum computer indeed exists to factor 15, which is 3 and 5 by the way, actually testing the scalability of the design has yet to be done. But once that happens, it could spell some worries in the field of encryption. One of the most popular encryption schemes uses factoring exactly because of how resource intensive the process is to decrypt a protect file or data, especially with larger numbers to be factored. With quantum computing, however, that could all be quite easy, especially if you can build a scalable machine such as Chuang's.

Of course, while some in the government might find that development interesting, there are those with less conscientious intentions that might be of the same sentiment. The good (or bad) news is that we are still far, far away from that ideal decrypting quantum computer. And even then, it will be an expensive computer that very few, like the government, can afford.