IIT-Delhi researchers achieve secure quantum communication for 380 km in standard telecom fiber

IIT-Delhi researchers have achieved an experimental breakthrough on secure quantum communication up to a distance of 380 kilometres in standard telecom fiber with a very low error rate that can be helpful in securing financial transactions and secret codes.

This long secure length is the highest achieved so far, not only in India but globally, for the Differential Phase Shift (DPS) QKD protocol, according to officials.

The results of the research by Indian Institute of Technology (IIT)-Delhi researchers has also been published in the 'Nature Scientific Reports' journal.

"Such low quantum bit error rate (QBER) makes the quantum communication resistance to collective and individual attacks and implementable for various applications, such as securing financial transactions, medical records and secret codes," said Bhaskar Kanseri, lead researcher and associate professor at IIT-Delhi's Physics Department and Optics and Photonics Centre.

"It is also capable of securing network communication such as Internet of Things (IoT) and ready to revolutionise the field of cyber security," Kanseri said.

He added that this realisation using state-of-the-art technology will not only help in reducing the need for trusted nodes for intercity or long-distance quantum key exchange, increasing the security of the cryptography scheme, but also prove to be a crucial step towards the commercial production of long-distance secure practical QKD devices.

In quantum communication, security is guaranteed by the laws of Quantum Physics and, in principle, it can not be broken even using a quantum computer, Kanseri explained.

"This QKD demonstration shows methods to get rid of the intermediate trusted nodes, which are the weak security loopholes and are vulnerable to several kinds of attacks. It paves ways for more secure long distance communication useful for strategic areas such as defence and online banking, making digital transactions safer in the near future," he said.