The first “unhackable” message was sent to Earth from the Chinese satellite, Micius, according to published reports. The Micius satellite is the world’s first quantum satellite and was launched by China last August.

On Aug. 10, however, the satellite successfully transmitted a message that is protected through the exploitation of quantum physics. Any attempt to eavesdrop or disrupt the message would result in detectable changes, giving everyone the peace of mind that their message and information was not touched.

Ground-based encryption using the same methods, entangled photons, has been possible for a while. The distance of a secure message cannot surpass 200 kilometers due to the cables gradually weakening the message’s security, introducing weak points that attackers can exploit.

The use of laser signals sent through the atmosphere give more promise, able to travel much farther before weakening. Using satellites, the potential transmission rate is about 20 times more efficient than using fiber-optic cables, Pan Jianwei, lead scientist on the experiment conducted by the state-run Chinese Academy of Sciences, told Reuters.

Although challenges remain, China continues to work on quantum communication with the hopes of developing a large, ground-based network to protect messages.