Researchers from the Max Planck Institute have demonstrated that equipment already in space can be adapted for secure data encryption, using the elusive property of photons to be found in different quantum states. Any attempt at hacking the system would be given away by another exotic phenomenon known in physics as “the observer effect.”
The paper, published in Optica, an online journal for breakthroughs in optics and photonics, reveals how quantum states have – for the first time– been measured so precisely from so far away. The team accomplished ground-based measurements of quantum states sent by a laser aboard a satellite 38,000 kilometers (23,600 miles) above Earth’s atmosphere.
Today’s math-based encryption mechanisms – used for securing everything from text messages to banking to health information – will be easily hackable by next-generation computers emerging in the next decade or so, experts believe. Therefore, a safer encryption method will soon be required. The researchers at Max Planck Institute believe they finally have the answer to that problem. From The Optical Society report:
“Rather than relying on math, quantum key distribution uses properties of light particles known as quantum states to encode and send the key needed to decrypt encoded data. If someone tries to measure the light particles to steal the key, it changes the particles’ behavior in a way that alerts the intended communicating parties that the key has been compromised and should not be used. The fact that this system detects eavesdropping means that secure communication is guaranteed.”
The most striking aspect of the research is the guarantee that any attempt at eavesdropping on quantum-encrypted communications will always change the quantum states of light particles, essentially destroying the information before it can be used.
What the OSA announcement implies – but doesn’t specifically mention – is that the new encryption method will mark the first truly practical application of the mysterious “observer effect” in physics – where any attempt at measuring a system, or any phenomenon for that matter, inevitably causes it to change. In this case, the decryption keys would get compromised before hackers get a chance to use them.
The researchers are working with Tesat-Spacecom and various players in the space industry to repurpose satellites’ laser communication systems and incorporate a quantum-based random key generator, as well as a way to post-process the keys. The authors believe the quantum encryption mechanism can be switched on in as little as 5 years from now.
Full research here: Quantum-limited measurements of optical signals from a geostationary satellite.