What has been hailed as the 'ultimate encryption' has seen information, or what's' known as quantum communication, successfully sent underwater for the first time.
Setting a new precedent, Chinese scientists from Shanghai Jiao Tong University sent information between entangled particles through sea water - a substance known for absorbing light.
The milestone is considered significant because quantum communication, or quantum teleportation, will allow people to send messages through water safe through from interference.
The experiment saw information transposed across a 3.3m long tank of seawater, and researchers expect the technique could be used to send unhackable communications close to 900m through open water.
Thomas Jennewein from the University of Waterloo in Canada told New Scientist underwater quantum communication had been discussed before, but previous to this attempt he wasn't aware of any other similar experiments.
An applied result of the technology would be secure communication from a submerged submarine, for example.
The concept is based on 'quantum entanglement' - a phenomenon Einstein once called "spooky action at a distance", which involves two quantum particles linking, and ultimately 'sharing' an existence. Meaning, what happens to one particle directly affects the other.
Through this, scientists have already 'teleported' information across significant distances through optical fibre and open space.
Earlier this year other Chinese researchers used quantum entanglement to teleport information to a satellite in Earth's orbit, across more than 500km.