|#1601||2311||July 05, 2016||By Puneet Bhalla|
Communication satellites relay data to support both military and commercial networks. The vulnerability of these communication links could be exploited to compromise sensitive information being transmitted through them. Quantum encryption is emerging as a promising technological option towards providing non-hackable communications. It involves transmitting of encoded data through a method called quantum key distribution (QKD), which relies on cryptographic keys transmitted via light-pulse signals. QKD uses quantum mechanics rather than conventional mathematical encryption technologies. Any attempt at interfering with the network, to eavesdrop, would result in a change in the quantum state of the data and this would be noticed by data flow monitors, resulting in aborting of the data transfer.
The world’s first functioning quantum cryptographic system was built in US. Subsequently, developments in quantum communications for transmission through fibre-optic cables and also through the Earth’s atmosphere have been pursued by many advanced countries. However, distances achieved have failed to cross 200 kilometres mark due to physical limitations of the technology. Consequently, only a few such linked systems over limited ranges and involving only a few devices are in operation worldwide.
China has been earnestly pursuing Quantum Communications under the leadership of Pan Jianwei, a professor of quantum physics at the University of Science and Technology of China (USTC) in Hefei. Experimental systems built in 2007 by Chinese and US physicists had reportedly achieved secure QKD transmissions between two points more than 100 kilometres apart. It first tested a secure network for exchanging information among government officials during a military parade in 2009. In 2012, it established terrestrial quantum communications network in Hefei linking some government devices and followed up in 2014 with a civilian focused network in Jinan. China is now building a 2000 kilometre terrestrial quantum communications network linking government offices in the cities of Beijing and Shanghai, which is expected to be completed by the year end.
It has also taken a lead in an effort to overcome the limitation of range by routing the data through satellites, which can then relay them to almost any place on Earth. Its scientists first tested this technology in space by bouncing photons off an orbiting German satellite (CHAMP) – which was covered with laser reflectors – and detecting them on Earth. As part of China's Strategic Priority Program on Space Science, the designing and construction for the first of its kind quantum communications satellite, the Quantum Experiments at Space Scale (QUESS), commenced in 2011.
Having completed the construction and testing, QUESS is expected to be launched in July 2016. Operated by China Academy of Sciences, the 500 kilogram experimental satellite would contain a quantum key communicator, quantum entanglement emitter, entanglement source, processing unit and a laser communicator. It would be launched on the Long March 2D rocket from the Jiuquan Satellite Launch Centre into an orbit at 1000 kilometres altitude.
China has collaborated with the Austrian Academy of Sciences to provide the optical receivers at a ground station in Vienna, while three more stations have also been planned across Austria. The test would involve transmission of encoded data through QKD. The link would first be established between a ground station in Beijing and the satellite and between the satellite and Vienna. Thereafter, it would endeavour to establish a link between Beijing and Vienna using the satellite as a relay. Once successful, more such satellites would be deployed and long term plans are to build a QKD system linking Asia and Europe by 2020 and have a worldwide quantum communications network in place by 2030.
The network would be utilised to secure government, military and diplomatic communications and it is being hailed as an important strategic asset for China. Its military role was underscored in one of Pan’s statement to the media: “China is completely capable of making full use of quantum communications in a regional war. The direction of development in the future calls for using relay satellites to realise quantum communications and control that covers the entire army.”  As per analysts, such a capability would provide an edge to China’s forces by providing secure space communications even as it attacks and degrades those of the adversary.
The technology also has commercial applications in sectors seeking secure transmission of personal and financial data. Pan had hinted at this when he said, “I hope that within another ten years of hard work, online transfers and payments can be guaranteed through quantum communication for every consumer.”
Quantum communication has its limitations and with the current capability is not suitable for mass use. Experts have also pointed out that while being more secure than conventional means of communication, it is not fool proof and is still prone to denial of service, equipment failure, physical tampering and human fallibility.
Beyond China, research on quantum communication technology is being undertaken in United States, Japan and Europe. In 2012, Europe had even proposed sending a quantum communications experiment to International Space Station but there has not been any further progress on the idea. The closest that any other country has progressed to pursuing it through space is Canada, where the government has funded a feasibility study on a proposed quantum key distribution microsatellite. Its University of Waterloo’s Institute for Quantum Computing (IQC) is developing a nano-satellite Quantum Encryption and Science Satellite (QEYSSat) whose mission objectives include demonstration of generation of encryption keys through the creation of quantum links between ground and space. The program however is still in nascent stages.
While securing their information against cyber hacking is on top of the agenda of most nations, China has taken a lead through its focussed efforts on quantum communications. It is now on the verge of demonstrating its capabilities both on ground and in space. While the technology might take few more years to mature, especially for the space element, the developments would be followed closely because of its strategic relevance.
The Author is Senior Fellow at CLAWS.Views expressed are personal.
 Yu Dawei, “In China, Quantum Communications Comes of Age”, Caixin Online, 02 June 2015, accessed at http://english.caixin.com/2015-02-06/100782139.html
 Huang Jin, “China-developed the world's first quantum satellite ready tobe lunched this July”, People's Daily Online, 08 March, 2016, accessed at http://en.people.cn/n3/2016/0308/c98649-9027010.html
 China Reveals First Space-Based Quantum Communications Experiment, MIT Technology Review, June 10, 2013, accessed at https://www.technologyreview.com/s/515871/china-reveals-first-space-based-quantum-communications-experiment/
 Sebastian Moss, “Why China built a quantum communications satellite”, DataCenterDynamics, 26 May 2016, accessed at http://www.datacenterdynamics.com/content-tracks/security-risk/why-china-built-a-quantum-communications-satellite/96259.fullarticle
 Lin, Singer, Costello, “China's Quantum Satellite Could Change Cryptography Forever”, Popular Science, 3March, 2016, accessed at http://www.popsci.com/chinas-quantum-satellite-could-change-cryptography-forever
 Europe Proposes Cheap Quantum Optics Link to the Space Station
November 13, 2012, https://www.technologyreview.com/s/507361/europe-proposes-cheap-quantum-optics-link-to-the-space-station/
 Quantum Encryption and Science Satellite (QEYSSat), Institute of Quantum Computing, University of Waterloo, accessed at https://uwaterloo.ca/institute-for-quantum-computing/qeyssat