Entry Date 11/9/17
You have heard of quantum physics—well, how about quantum computing? According to Paul Teich (Why can nobody have a last name that spell-check recognizes?) in his article “Quantum Computing Will Not Break Your Encryption, Yet,” companies such as Microsoft, Google, and IBM, as well as “a host of academic and national research labs[,]” are working hard to achieve quantum computing.
Teich researched extensively to even be able to write his brief overview of the mechanics behind quantum computing. I will provide an even briefer summary of how it all works. Firstly, a quantum computing (QC) “architecture is based on ‘qubits’ [(pronounced cubits)] instead of binary computer bits.” As I understand it, qubits are some sort of quantum particle that can change states in certain ways, but neither I nor Teich understand exactly what they are or why they work—that is not important for this article.
Teich uses the following analogy: Imagine “the waves generated by throwing a handful of small floating balls into a pool of water.” The intersections of the ripples that form by throwing these balls into the water “changes the up/down position of each of the balls in interesting patterns.” As I understand it, these ups and downs represent the binary 1s and 0s in computer code. “[T]he relative position of each ball and the order in which they hit the water is the program.” When the program is finished, the “the position of each ball is measured, and that collection of measurements is the result of a QC program.”
In order to see the result of a program, the qubits need to stand still. “This is a lot harder than it sounds. “First, it requires freezing the qubits to nearly ‘absolute zero’ just to have a fighting chance of keeping them in proper working order until a calculation is finished.” Achieving absolute zero (0ºK / -459.67ºF / -273.15ºC) is physically impossible to achieve, and qubits need to be at 0.01ºK/ -459.65ºF / -273.14ºC to work properly.
As if that were not hard enough, you have to deal with particles changing states when you look at them. If you have heard anything about quantum physics, you have probably heard that the act of observing a quantum particle changes its state. In QC, “[d]irectly observing a qubit ends a program” (I am just imagining a ring of scientists not watching a QC program take place.).
“Well, shoot,” the audience says. “We cannot check the state of a program until it is done, which means we cannot fix errors while a program is running.” Very astute, audience! Teich brings up this very concept. Scientists “need to design error detection and correction into each qubit.” The current solution to this problem is to use two types of qubits: logical qubits and physical qubits.
Logical qubits are called “fault-tolerant” qubits. These are the qubits with error detection and correction. As I understand it, logical qubits are the ones that change when you look at them. “QC architectures must entangle extra [physical] qubits with a computing qubit, so a QC program can infer the state of a computing qubit without directly observing it[.]”
When scientists achieve this interaction of physical and logical qubits, then QC programs will be unfathomably fast at computing. “QC has the potential to quickly solve problems that are impossible to calculate in useful timeframes (or even human lifetimes) today.” For example, a QC program might be able to crack a 128-bit encryption key (something that is considered all but impossible today) in a short enough time to be useful.
Here’s the rub: “Today’s state-of-the-art [in quantum computing] is that no one has publicly shown even a single functional logical qubit.” Human kind is nowhere near creating a working QC program with logical and physical qubits working together. “There are some near-term applications for physical qubits: mostly solving optimization and quantum chemistry problems.” But companies do not plan to commercialize physical qubit applications for another five to ten years, let alone logical qubits.
Teich says, “All the QC researchers I have talked with say that shipping a commercial QC accelerator based on logical qubits is still at least 15 years away[.]” In other words, you should not have to worry about your encryption getting hacked by a QC program until “the early 2030s at the soonest.”
In conclusion, I am somewhat relieved. When I heard my professor talking about quantum computing being able to break encryption, I was worried. However, with such a large time-frame to work with, I think security professionals will be able to come up with a way to protect sensitive data from quantum computers. Teich indicates that “[t]he US National Institute of Standards and Technology (NIST) is working on detailed recommendations for a post-QC cryptography world.” The institute actually “issued a formal call for proposals” (The submission deadline is November 30th, so break out your quantum physics and encryption textbooks and get working!) In short, I am holding out hope for the world of security.
Source: https://www.forbes.com/sites/tiriasresearch/2017/10/23/quantum-will-not-break-encryption-yet/
Security Dragon 