600 KM Quantum Encryption Transmission

Recently studied a company doing something similar, over considerably less distance.  Will this continue to expand?   Implications? 

Quantum-Encrypted Information Transmitted Over Fiber More Than 600 Km Long   By Optica  October 25, 2021  in CACM

Researchers at the University of Leeds and Toshiba Europe in the U.K. established secure quantum communication over 605 kilometers (375 miles) of fiber through a new signal stabilization method.

The researchers used the twin-field quantum key distribution protocol, which enables two geographically separated users to establish a common secret bit-string by sharing photons, which are usually transmitted over an optical fiber.

The stabilization technique utilizes two optical reference signals at different wavelengths to minimize phase fluctuations over long distances.

The researchers demonstrated that this method could support repeater-like performance while accommodating losses outside the traditional limit of 100 decibels over a 605-kilometer-long quantum channel.

Toshiba Europe's Andrew Shields said, "This will allow us to build national- and continental-scale fiber networks connecting major metropolitan areas."

From Optica    View Full Article  

Toshiba Simulations Beat Quantum Computing

Toshiba work of interest.  Linking to Microsoft Cloud.  Would you expect a simulation to beat out an actual implementation?  Depends.  But a simulation usually means it does not include all the physical constraints involved.  Note the mention of 'combinatorial' problems ....that is problems that have very large numbers of possible solutions, exactly what we posed very early on.

Commissioned by CACM Staff

Why wait for quantum computers to be perfected "someday," when you can use Toshiba's quasi-quantum optimization algorithm on Microsoft's Azure cloud in 2021? It outperforms today's fledgling quantum computer speeds through the use of that proprietary algorithm on conventional digital computers accelerated with cloud GPUs [graphic processing units].

Alternatively, the quasi-quantum algorithms can run on Toshiba's FPGA [field programmable gate array].

"It will take a very long time for quantum computers to achieve the high performance of our [GPU and FPGA-powered] optimization solutions for large-size problems," said Hayato Goto, chief research Scientist at Toshiba Corp. in Japan. In fact, Goto said, "So far, no one has even been able to prove that any future quantum computer will be able to solve combinatorial optimization problems faster, which leaves room for our classical machines to surpass quantum computers."

Too good to be true? Toshiba recently demonstrated a discrete version of its quasi-quantum algorithm in peer-reviewed benchmarks against a wide variety of current-day quantum computer hardware and quasi-quantum software simulators, and outperformed them all.... " 

Toshiba Targets Quantum Cryptography

Considerable effort under way here:

Toshiba targets $3 billion revenue in quantum cryptography by 2030

By Makiko Yamazaki in Reuters

TOKYO (Reuters) - Toshiba Corp 6502.T said on Monday it aims to generate $3 billion in revenue from its advanced cryptographic technology for data protection by 2030, as the Japanese sprawling conglomerate scrambles to find future growth drivers.

The cyber security technology, called quantum key distribution (QKD), leverages the nature of quantum physics to provide two remote parties with cryptographic keys that are immune to cyberattacks driven by quantum computers.  ... 

New Combinatorial Optimization Algorithm

Combinatorics are of particular interest to me, are part of any kind of complex process choice problem.  Note the use of annealing, being used in some quantum methods.  Here a new advance, examining.

Optimization Algorithm Sets Speed Record for Solving Combinatorial Problems
IEEE Spectrum
John Boyd
February 10, 2020

Researchers at Toshiba Corp. in Japan have developed a quantum-inspired heuristics algorithm that is 10 times faster than competing technologies. In October, the researchers announced a prototype device implementing the algorithm that can detect and execute optimal arbitrage opportunities from among eight currency combinations in real time. The researchers claim the likelihood of the algorithm finding the most profitable arbitrage opportunities is greater than 90%. The team implemented the Simulated Bifurcation Algorithm on a single flat-panel gate array (FPGA) chip, and were able to run 8,000 operations in parallel to solve a 2,000-spin problem. In a separate test using eight GPUs, the system solved a 100,000-spin problem in 10 seconds—1,000 times faster than when using standard optimized simulated annealing software.  .... " 

Encryption via Quantum Mechanics

Related capability suggested here.

Toshiba devises way to send encrypted messages using quantum mechanics

Toshiba plans to demonstrate a working prototype within two years

Toshiba claims to have uncovered a way use the laws of quantum mechanics to send super-secure encrypted messages.

In Toshiba's previous research into quantum cryptography, it found that bits are carried and transmitted on individual photons, which cannot be read-out without leaving errors as evidence of the intrusion and, thanks to this property, it is possible to test and guarantee the secrecy of quantum keys.

The Japanese company has claimed for a while now that quantum cryptography realises secure transfers of all manner of confidential information, including biometric data and genomic data. ... "