Lifeboat Foundation

Quantum key distribution (QKD)^1,2,3 is a theoretically secure way of sharing secret keys between remote users. It has been demonstrated in a laboratory over a coiled optical fibre up to 404 kilometres long^4,5,6,7. In the field, point-to-point QKD has been achieved from a satellite to a ground station up to 1,200 kilometres away^8,9,10. However, real-world QKD-based cryptography targets physically separated users on the Earth, for which the maximum distance has been about 100 kilometres^11,12. The use of trusted relays can extend these distances from across a typical metropolitan area^13,14,15,16 to intercity¹⁷ and even intercontinental distances¹⁸. However, relays pose security risks, which can be avoided by using entanglement-based QKD, which has inherent source-independent security^19,20. Long-distance entanglement distribution can be realized using quantum repeaters²¹, but the related technology is still immature for practical implementations²². The obvious alternative for extending the range of quantum communication without compromising its security is satellite-based QKD, but so far satellite-based entanglement distribution has not been efficient²³ enough to support QKD. Here we demonstrate entanglement-based QKD between two ground stations separated by 1,120 kilometres at a finite secret-key rate of 0.12 bits per second, without the need for trusted relays. Entangled photon pairs were distributed via two bidirectional downlinks from the Micius satellite to two ground observatories in Delingha and Nanshan in China. The development of a high-efficiency telescope and follow-up optics crucially improved the link efficiency. The generated keys are secure for realistic devices, because our ground receivers were carefully designed to guarantee fair sampling and immunity to all known side channels^24,25. Our method not only increases the secure distance on the ground tenfold but also increases the practical security of QKD to an unprecedented level.

https://youtube.com/watch?v=awnuJaEDVc4

Were they paratroopers with flashlights, satellites or, as Internet users point out, a flying saucer?

SpaceX successfully launched its first Starlink rideshare mission into orbit today (June 13), lofting 58 Starlink internet satellites along with three Earth-observation satellites before nailing a rocket landing at sea.

SpaceX updated the website for its Starlink satellite internet project on Friday, as the company continues to move closer to its goal of offering direct-to-consumer broadband from space later this year.

“Get updates on Starlink news and service availability in your area,” the website reads, with a submission form for an email address and zip code. The form allows prospective customers to apply for updates and access to a public beta test of the Starlink service.

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Radio waves travel poorly through the water, which makes it difficult for divers or submersibles to wirelessly transmit information to the surface. Scientists are trying to change that, though, by developing an underwater version of Wi-Fi.

Back in 2018, we heard how researchers at Saudi Arabia’s King Abdullah University of Science and Technology (KAUST) had used lasers to transmit HD video through water. Their experimental new system, known as Aqua-Fi, builds on that technology.

A user such as a scuba diver would start by sending data (such as photos or videos) from a smartphone contained in a watertight housing. That data would initially be transmitted in the form of radio waves, going just a few feet to a small device mounted on the diver’s air tanks.

A bug in a protocol used by virtually all Internet of Things devices exposes millions of users to potential attack, a researcher reported Monday. The fault centers on the Universal Plug and Play protocol, a 12-year-old implementation that simplifies connections among network devices such as computers, printers, mobile devices and Wi-Fi access points.

Billions of devices are theoretically vulnerable, the report stated, but only those with UPnP activated currently face risk of attack.

Turkish security engineer Yunus Çadirci uncovered the UPnP bug, named CallStranger, that could be exploited to gain access to any smart device such as security cameras, printers and routers that are connected to the Internet. Once access is gained, malicious code can be sent through network firewalls and other security defenses and reach internal data banks.

SpaceX has promised that future Starlink satellites will have sunshades so they don’t blocks astronomers’ views of the stars.

Aquatic internet that sends data through light beams could enable divers to instantly transmit footage from under the sea to the surface.

The internet is an indispensable communication tool, connecting tens of billions of devices worldwide, and yet we struggle to connect to the web from under water. “People from both academia and industry want to monitor and explore underwater environments in detail,” explains the first author, Basem Shihada. Wireless internet under the sea would enable divers to talk without hand signals and send live data to the surface.

Underwater communication is possible with radio, acoustic and visible light signals. However, radio can only carry data over short distances, while acoustic signals support long distances, but with a very limited data rate. Visible light can travel far and carry lots of data, but the narrow light beams require a clear line of sight between the transmitters and receivers.