Google's "quantum supremacy" is not the end of encryption

Google accidentally made the computer history last week. In recent years, the company has been competing more and more with competitors such as IBM and Intel to develop quantum computers, which promises considerable power over some issues by using quantum physics. The research company attempted to stand out by claiming that its prototypes of quantum processors were about to demonstrate "quantum supremacy," an evocative phrase referring to an experiment in which a quantum computer surpasses that of a computer classic. One of Google's top researchers predicted that the company would achieve this goal in 2017.

Friday, the news has slipped that Google had reached the cap. the Financial Times drew attention to a research project that had been quietly published on a NASA website in which Google researchers describe the achievement of quantum supremacy. In a few hours, the Democratic presidential candidate Andrew Yang was Warning that Google quantum computers could break encryption, and quantum scientists have tried to assure the world that conventional computers and security are not obsolete.

The experts are impressed by the feat of Google. John Preskill, a professor at Caltech who coined the term quantum supremacy in 2011, calls the concept "a truly impressive result in experimental physics". ready for practical work.

"The problem that their machine solves with amazing speed has been chosen carefully for the sole purpose of demonstrating the superiority of the quantum computer," Preskill says. It is not known how long quantum computers will take to become commercially useful; breaking the encryption – a theoretical use of technology – remains a distant hope. "There are still many years left," says Jonathan Dowling, a professor at Louisiana State University.

Google's classic computers may have outgrown the work of its quantum computers. Dowling said other researchers and he had been informed of the breakthrough announced last week after a Google Scholar alert led them to the draft document. The company is working with NASA, which may have published it as part of a pre-publication review process. Google declined to comment. NASA has not responded to a request for comment.

Google and others are working on quantum computers, because they promise to solve some problems that may not last long on conventional computers. The approach seeks to exploit the mathematics that underlie the quirks of quantum mechanics, such as how photons can appear to act simultaneously as waves and particles. In the 1990s, researchers showed that this could be a powerful new way to reduce numbers. Interest in the field was boosted after a Bell Labs researcher created an algorithm that a quantum computer could use to crack long encryption keys, thus showing how technology could advance conventional machines.

More recently, academic and corporate researchers have developed prototypes of quantum processors and have touted the use cases of chemistry and machine learning. These devices can now exploit data, but they are still too small and error-prone to allow conventional computers to get into hands-on work. Preskill coined the term quantum supremacy in a 2011 talk about how researchers could prove that quantum hardware actually offers advantages over conventional computers.

Google, IBM, Intel, Microsoft and several startups have significantly increased investment in quantum computing since then. This made the moment of quantum supremacy inevitable. "It's something we hoped for maybe sooner than later," says Dowling.

One of the reasons for this expectation was what Google's own researchers said. In 2017, John Martinis, who leads quantum research, predicted that his team would achieve supremacy by the end of this year. Google, IBM, and Intel have all introduced quantum processors with about 50 qubits, devices that make up the building blocks of quantum computers, about the size expected by experts to demonstrate quantum supremacy.