Quantum encryption of light speed operation

Quantum encryption of light speed operation

Imagine the following three scenarios: Hospitals send MRI results directly to your mobile phone without worrying about your personal health data leakage; learn that your financial information is safe to store on servers other than half the world; send highly sensitive business letters without worrying that it will fall into the bad guys.

The University of Toronto's engineer team conducted a new study, making us one step closer to achieving secure information exchange. The investigator's paper is published in Nature Communications, a network journal under Nature journal group. This paper introduces a all-photon quantum ultimate protocol, this allows you to use a quantum password to ensure data security during long-distance transmission.

The communication process using quantum cryptography uses the law of quantum mechanics to transmit information between two users. It is encoded through the quantum state of the photon, and communication encryption is very secure and almost impossible to be broken. However, sending photon in ultra-long optical fiber is not as simple as it looks: If the optical fiber length exceeds 50 km, more than 90% of photon will be lost, which severely limits the range of quantum communication.

To expand this transmission range, many studies have concentrated on developing "quantum relay" to stimulate photon and reduce energy loss. Similar to small quantum computers, these relay protects and stores entangled photon signals in low-temperature optical fibers, resulting in low-frequency quantum communication and the equipment itself being bulky and slow.

A team from the University of Toronto developed a new quantum repeater that uses only photon for long-distance transmission without the need for actual Quantum memory, it also does not need to be designed at the junction between material and light. A professor of physics at the University of Toronto and Japanese telecom phone Co., Ltd. jointly conducted the project.

People are very interested in designing the quantum Internet. This new network structure will allow people to transmit more information and be more powerful. However, the quantum states used in technology may also be very fragile. The team's original intention was to design a secure and reliable long-distance communication method.

All-photon quantum communication proposed by the team can support higher quantum communication frequencies. It uses technology to demonstrate mature optical elements and can run at room temperature. This technology uses high-quantum entangled state (cluster state) at the basic level, which can increase the fault tolerance of the system.

All-photon quantum communication can be used to establish a network between quantum computers. Quantum computers have not yet been implemented, and research institutions around the world are fiercely competitive in the Development of quantum computers.

In the future, we may establish a quantum Internet composed of quantum computers. The basic function of the Internet is to transmit information, but the current communication model is not secure and there are many signal losses.

Quantum computers are coming soon, but there is another field that sounds like science fiction: quantum transmission.

The initial question raised by the researchers was the ability to transmit quantum polarization over long distances, but this was boring. Later, the researchers asked themselves, what more interesting things can we do? What we can do is quantum transmission.

Although we cannot transfer people from home to the company in the short term, the researchers have completed a series of tests, it proves that the state of a quantum or even an atom can be transmitted from one location to another.

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