Is the promise of quantum computing supremacy bunk?

[Whitehall_Bin_Men]

The promise of quantum computing supremacy is bunk
by COLIN EARL — 4 days ago in CONTRIBUTORS
The promise of quantum computing supremacy is bunk
https://thenextweb.com/contributors/2018/06/02/quantum-computing-is-bu nk/

Google recently announced that the first demonstration of quantum supremacy could be just a few months away. I think they are entirely wrong. It is not just more than a few months away, it is forever away.

I explain why below, but first I would like to take exception to their use of the word “supremacy” because what they are promising should not be called “quantum supremacy,” but one very narrow and specially constructed case in which quantum computing is better than traditional computing.

To call this supremacy makes as much sense as claiming that strips of magnesium enjoy supremacy over electric bulbs for the generation of light. Yes, there is a specific use case for which they are superior, but to say that they enjoy “supremacy” is a grotesque misuse of language; or, clever marketing if you prefer.

A more accurate term than “supremacy” would be “not entirely useless”. In case you were wondering, the magnesium use case is the temporary illumination of Austrian ice caves for the edification of tourists.

Now, back to quantum computing.
One reason for doubting the latest cheery announcements is simply the field’s long and unbroken series of failed promises. Researchers have been predicting such a breakthrough “within the next decade” for almost forty years now and despite the billions of dollars poured into development, the target date keeps retreating.

Further, doubts are now being expressed by mathematicians, computer scientists, and physicists. Doubts grounded in technical analyses which have gone a long way towards proving that the task is not just extremely difficult, but theoretically impossible.

For an overview, here is an excellent article from Quanta Magazine. Among other insights, it points out that the computational power of quantum systems is limited if they are noisy. While the quantum boosters seem to believe that noise is just an engineering problem, I believe that it is absolutely fundamental. In part because computers are entropy engines.

For example, when a large number is decomposed into its prime factors, the entropy of these factors is lower than that of the original number. Since the entropy of the universe tends to increase, the net result of the computation must always be an increase in overall entropy, i.e. noise.

The promise of quantum computers is that as the number of qubits rises, their computational power to perform such calculations rises exponentially – if only the quantum state could be kept from decaying. But as the computational power of the system rises exponentially with the number of qubits, the amount of energy that must be converted into noise also rises exponentially.

Noise is not a crippling problem for traditional computers – their circuits can be made robust enough to stand some noise and whisk it away in the form of heat.

But the quantum state is intrinsically fragile and destroyed by noise. There are attempts to address this challenge with error correcting quantum circuits, but these mechanisms would also have to scale exponentially with the qubit count. They can’t. And so quantum computers will never be usable.

This is not to say that quantum techniques are without value. For example, they can improve cryptography with a defense against man in the middle attacks that is unbreakable. But for general computational tasks, such as factoring large numbers, they are, and will, remain worthless.

To be specific, I do not believe that a quantum computer will ever do a better job of factoring a large number than the 8-year-old Intel i7 950 running the PC on which I typed this article. And at just $300, it is quite a bargain in comparison to the $15M that a quantum computer can cost.

[TonyGosling]

Google Achieves ‘Quantum Supremacy’ That Will Soon Break All Encryptions
BY CHRISS STREET
5 Comments September 25, 2019 Updated: September 25, 2019 Share

News Analysis
https://www.theepochtimes.com/google-achieves-quantum-supremacy-that-w ill-soon-break-all-encryptions_3096063.html

Bitcoin plunged by 15 percent as the tech world begins to realize that Google achieving “quantum supremacy” computing threatens all financial and military cyber-security.

TradingView data reported on Sept. 24 that Bitcoin crypto-currency on the Binance exchange crashed from $9,352.89 to about $7,800 in less than an hour trading, before closing at about $8,568. The loss of confidence follows the release of technical reports that “quantum supremacy” computing will soon be able to hack 256-bit encryptions that are invulnerable to traditional supercomputer brute force attacks.

Google’s efforts over the last decade to develop a ‘Super Intellect System’ focused on advancing artificial intelligence (AI), quantum computing and humanoid robotics. Many observers have referred to the effort as “Skynet,” from the 1984 movie: “The Terminator.”

NASA published a scientific paper stating Google achieved “quantum supremacy” with a 53-qubit quantum computer. The device takes just 200 seconds to complete a computing task that would normally require 10,000 years on a new supercomputer.

Although a 53-qubit quantum computer can break any 53-bit cryptography in a few seconds, Bitcoin transactions are protected by 256-bit encryption. But Fortune reported that Google quantum computer qubits will double at least every two years to over 100 qubits by 2020, and then defeat all crypto-currencies in 2022 with over 400 qubits.


The Defense Information Systems Agency (DISA) disclosed in March that quantum computers will eventually expand their qubits into the 512, 1024 and 2048 range, rendering the highest levels of current U.S. military encryptions obsolete. DISA is relying on the Department of Defense’s ‘Other Transaction Authority’ to expedite issuing requests for whitepapers on potential cybersecurity encryption models that cannot be hacked by quantum computers.

Quantum computing leapfrogs the limitations of traditional computing where calculations are done one at a time with the two binary digits (bits) of “0” or “1” that turn on and off electronic current flowing through transistors. But quantum superposition subatomic particles can exist in two states at once, expanding the “entangled” digits into qubits.

IBM CIO Fletcher Previn speaking at the Baltimore AFCEA TechNet Cyber conference in March described the quantum computing challenge: “It’s a completely different approach to computing than counting, which is the basis of all current computing. It’s possible we’ve been programming computers the wrong way for the last X number of years. Quantum is a much closer approximation to how nature figures things out.”

Chinese leader Xi Jinping demanded the complete modernization of the People’s Liberation Army (PLA) by 2035 and China’s transition to a major military power by 2050. To support the effort, China’s 2019 military spending grew by 7.5 per cent. But its PLA dominated technological research budget grew by 13.4 percent, with special focus on integration of AI, quantum computing, humanoid robots.

It was assumed in early 2018 that China would be the first to achieve quantum supremacy after Chinese physicists claimed to set a quantum computing record by achieving 18-qubit entanglement, while still being able to control each qubit. But China has not made any comment regarding quantum computing since Google disclosed getting there first.

Demonstrating the accelerating speed of disruptive technical change, D-Wave—which provides exotic hardware to Google and other research organizations—announced on Sept. 24 that the company is offering a 2048-qubit quantum computer called the “D-Wave 2000Q” platform.

Chriss Street is an expert in macroeconomics, technology, and national security. He has served as CEO of several companies and is an active writer with more than 1,500 publications. He also regularly provides strategy lectures to graduate students at top Southern California universities.