Quantum Crypto Wins Turing Award

Quanta magazine announces:

Bennett and Brassard have now been named the winners of the A.M. Turing Award, one of the highest honors in computing, for “their essential role in establishing the foundations of quantum information science and transforming secure communication and computing.” The award comes with a $1 million prize.

No, they did not transform secure communications. Their work has no practical applications.

Scott Aaronson says:

This is the first-ever Turing Award specifically for quantum stuff (though previous Turing Award winners, including Andy Yao, Leslie Valiant, and Avi Wigderson, have had quantum among their interests).

As a practical proposal, BB84 is already technologically feasible but has struggled to find an economic niche, in a world where conventional public-key encryption already solves much the same problem using only the standard Internet—and where, even after scalable quantum computers become able to break many of our current encryption schemes, post-quantum encryption (again running on the standard Internet) stands ready to replace those schemes. Nevertheless, as an idea, BB84 has already been transformative, playing a central role in the birth of quantum information science itself.

The BB84 protocol suffers several technical flaws.

The most important thing in secure communications is authentication. This is currently done with digital signatures and certificates, using RSA or ECDSA. This underlies everything. It is the most important part of ubiquitous protocols like https and ssh. But the quantum crypto cannot do it. That makes it useless for anything serious.

The next fatal defect is that it depends on hardware quirks. You have to have analog equipment that may or may not have the required precision, and may have analog vulnerabilities. This makes is subject to hardware attacks.

This makes is vastly inferior to the math-based crypto methods, because the math is not subject to hardware attacks. If a digital crypto device outputs bits that do not have the desired voltage or frequency, no info is leaked.

Another flaw is that the main BB84 security guarantee is that an attacker can probably be detected, so that transmission can be terminated. This has no value. In today's internet, systems get attacked all the time, and no one wants to shut down a communication because it is being attacked. Conventional cryptosystems are designed to be immune to such attacks.

Another flaw is that the internet is run on millions of routers. Using quantum crypto requires that all those routers be quantum computer routers. The quantum router has not even been invented, and even if it is possible, it will never be economical or have the necessary throughput.

All this has been known for decades, and that is why no one uses it, except for a few research demo projects.

New Survey Article on Many-Worlds

I regularly bash many-worlds theory as unscientific and nonsensical, but it is useful to see how it is defended by its proponents. Here is a new encyclopedia article on the subject.

The Everett or Many Worlds interpretation is claimed to be the only realist interpretation that can recover the empirical success of quantum theory in its relativistic and non-relativistic variants, its advocates suggest that it does so without any additions to the physics.

Yes, it claims that, but it has never recovered any empirical success. None.

Probability within Everettian theories is strongly contested and it’s un- clear whether the many distinct resolutions in the literature are mutually incompatible and thus undermine one another ...

EQM [Everettian Quantum Mechanics, ie many-worlds theory] is taken to face two major problems: the preferred basis problem and the probability problem. The preferred basis problem concerns how the universal wavefunction is decomposed, leading to different classical-like branches. ...

The second major problem is the probability problem, which asks how probability can make sense in a deterministic theory where all possible outcomes occur.

Yes, those are two big problems. They cannot define the branches or the probabilities.

The article also discusses other approaches like Bohmian mechanics, and how they do not work either. The obvious inference is that the textbook Copenhagen interpretation of 1930 works better than any of these more modern ideas.

Has Quantum Supremacy been Achieved?

Dominik Hangleiter writes in a new paper:

Recently, I gave a couple of perspective talks on quantum advantage, one at the annual retreat of the CIQC and one at a recent KITP programme. I started off by polling the audience on who believed quantum advantage had been achieved. Just this one, simple question.

The audience was mostly experimental and theoretical physicists with a few CS theory folks sprinkled in. I was sure that these audiences would be overwhelmingly convinced of the successful demonstration of quantum advantage. After all, more than half a decade has passed since the first experimental claim [AAB+19] of “quantum supremacy” as John Preskill called the idea “to perform tasks with controlled quantum systems going beyond what can be achieved with ordinary digital computers” ...

I could not have been more wrong: In both talks, less than half of the people in the audience thought that quantum advantage had been achieved.

After several pages describing the experiments, he concludes:

I hope that I could convince you that quantum advantage has been achieved. There are some open loopholes, but if you are happy with physics-level experimental evidence, then you should be convinced that the RCS experiments of the past years have demonstrated quantum advantage.

No. The whole point of quantum supremacy, aka advantage, is to do an experiment that convincingly demonstrates that super-Turing computers are possible. If most of the experts have not been convinced, then the principle has not be demonstrated.

I am a skeptic, and will be hard to convince. But they have not even convinced the experts who work in the field.

But read the paper, and make up your own mind.

Scott Aaronson seems to be still on the fence. His recent postings have been either about how he hates Pres. Trump, or how he agrees with Trump's pro-Israel foreign policy.

Science Papers are now mainly read by AI LLMs

Alexander Kustov, with Claude AI assistance, writes Academics Need to Wake Up on AI and Part II:

1. AI can already do social science research better than most professors.

2. The academic paper is a dead format walking.

3. The commercial journal system may not survive this.

4. Academics hold AI to absurd double standards.

In particular: Most papers are already mostly read by AI, not humans. Your primary audience is increasingly LLMs.

Physics Lifetime: 1820 to 1970

Popular tweet:

Many people don't understand just how brutal diminishing returns in theoretical physics were.

Physics barely existed before 1820. After 1970, there was essentially nothing left to discover.

In 1819 there were probably less than 100 full-time paid physicists in the whole world.

By 2026 there are probably about a million physicists across academia and industry, and that number was already huge in the 1970s when physics sort of "ended" with QCD and electroweak unification.

A small, brave band of gentlemen-scholars and amateurs worked out the most important parts of physical law in the 1800s. People doing it as a hobby!

Today, vast armies of professionals equipped with supercomputers toil away in the quantum gravity dungeon, unable to make progress.

Diminishing returns are brutal.

my point is that the low hanging fruits of physics were all picked in a brief window from about 1820 to 1970.

Before that, it was difficult to get anything done at all, there was no funding

Quantum Computing and National Security

The Wash. Times reports:

One of the most advanced technologies intersecting with U.S. national security today is quantum computing. Quantum has arrived in 2026, and how it ultimately gets implemented will impact America’s standing in great power geopolitical competition, especially with U.S. adversaries. National Security Editor Guy Taylor sits down with industry leaders at “Qubits26 Quantum Realized,” a conference hosted by D-Wave Quantum, for a wide-ranging discussion on what quantum computing is and how it stands to change the world.

The rest of the article is paywalled, and I do not need to read it. It is all a scam. Quantum computers will not affect national security.

Good Wlll Hunting

SciAm reprints an article on Why mathematicians hate Good Will Hunting.

With the award ceremony for the Oscars this month, many people are thinking back on past winners—including Good Will Hunting. It’s worth taking a closer look at the blackboard in a film that, in 1997, took nine nominations and won for both original screenplay and actor in a supporting role. ...

But I still think the filmmakers chose this particular math problem poorly, even for a Hollywood film.

No, that is not why mathematicians hate the movie.

The hero is a fictional exceptionally talented math prodigy. Supposedly he enjoys math so much that he gets a job as an MIT janitor, and eavesdrop on the research there.

But he never spends any of his free time doing math. Instead he goes drinking with his non-math buddies, and getting into fights. In the end, he decides that math is for losers, and he abandons a wonderful math opportunity in favor of chasing a girlfriend.

Nobody gets that good at math unless he enjoys it very much. The movie fails to portray that at all.