Quantum communication using entangled particles is essentially unhackable, and now it has been extended to the longest distance ever, about 1200 kilometres
Source:
https://www.newscientist.com/article/2245885-chinas-quantum-satellite-helps-send-secure-messages-over-1200km/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home