On Monday, Indian Space Research Organisation (ISRO) announced that it has successfully demonstrated free-space Quantum Communication over a distance of 300 m. According to ISRO, this is a major milestone for unconditionally secured satellite data communication using quantum technologies. With this breakthrough, India joins a handful of other nations such as the US, the UK, Canada, China and Japan who have made significant contributions in the field of quantum communication.
ISRO demonstrated their quantum capabilities by live video conferencing using quantum-key-encrypted signals. The free-space quantum key distribution(QKD) was demonstrated at Space Applications Centre (SAC), Ahmedabad, between two line-of-sight buildings within the campus. The experiment was performed at night to ensure that there is no interference of the direct sunlight. Most of the mission critical technologies used in the experiments were built by ISRO in-house, which includes the NAVIC receiver for time synchronization between the transmitter and receiver modules, and gimbal mechanism systems instead of bulky large-aperture telescopes for optical alignment.
Quantum Key Distribution allows to generate and distribute a secret key which can be used to encrypt or decrypt a message. Thanks to quantum phenomena like quantum entanglement, the presence of a third party between a sender and receiver can be identified hence securing the data transmission.
“The Quantum Key Distribution (QKD) technology underpins Quantum Communication technology that ensures unconditional data security by virtue of the principles of quantum mechanics, which is not possible with the conventional encryption systems. The conventional cryptosystems used for data-encryption rely on the complexity of mathematical algorithms, whereas the security offered by quantum communication is based on the laws of Physics. Therefore, quantum cryptography is considered as ‘future-proof’, since no future advancements in the computational power can break quantum-cryptosystems,” said ISRO in their statement.
The success of this experiment will pave the way for a highly secured satellite based quantum communication as ISRO gears up to establish contact between two Indian ground stations as part of their next experiment.