Quantum communication

IN NEWS:

• Chinese scientists have achieved the world's first quantum key distribution over 1,120 kilometers without relying on any intermediate security relays.

ABOUT:

• Today, sensitive data is typically encrypted and then sent across fiber-optic cables and other channels together with the digital “keys” needed to decode the information. The data and the keys are sent as classical bits—a stream of electrical or optical pulses representing 1s and 0s. And that makes them vulnerable. Smart hackers can read and copy bits in transit without leaving a trace.
• Quantum communication takes advantage of the laws of quantum physics to protect data.
• These laws allow particles—typically photons of light for transmitting data along optical cables—to take on a state of superposition, which means they can represent multiple combinations of 1 and 0 simultaneously. The particles are known as quantum bits, or qubits.
• If a hacker tries to observe qubits in transit, their super-fragile quantum state “collapses” to either 1 or 0. This means a hacker can’t tamper with the qubits without leaving behind a sign of the activity.
• Some companies have taken advantage of this property to create networks for transmitting highly sensitive data based on a process called quantum key distribution, or QKD.

MICIUS Satelite:

• China launched a dedicated quantum communications satellite called Micius in 2016.
• In 2017 the satellite helped stage the world’s first intercontinental, QKD-secured video conference, between Beijing and Vienna.
• Recently using MICIUS the world's first quantum key distribution over 1,120 kilometers without relying on any intermediate security relays was achieved.
• Usually QKD via optical fibers are susceptible to interference and cannot be sent over ultralong distance without relying on intermediate repeaters to boost the signals.
• Use of MICIUS to send secret keys has now reduced the limitation.

PRELIMS QUESTION:

Q. ‘MICIUS’ is a satellite launched by:

1. Russia
2. Japan
3. USA
4. China

Answer to Prelims question