Researchers based in Austria have overcome the limitation of encryption between more than two participants. This is via a proof-of-concept quantum physics experiment. Here the scientists have connected four participants within a quantum network. In the trial, each participant was able to send an encrypted message with each other person.
The future-state quantum Internet promises a completely hack-proof communication between users worldwide. Current communications technology relies on light signals; the future state is to use individual light particles (photons) to produce a cryptographic key. This light-key is then used to encrypt data, and the data can be transmitted via conventional means. Effectively, each participant is measuring the polarization of a photon as it is received.
When the recipient receives the data, provided they have the same key, they will be capable of decrypting the data. The reason this process is so secure is because of a fundamental quantum physical law: it is impossible to copy the state of a single light particle without errors. For this reason, EE News Europe reports, many quantum physicists state that it is not possible to hack such a message.
If an interloper attempts to read the encoded data, the quantum state will be changed (this is referred to as the ‘No-Cloning Theorem’). In practice this will mean that when a third party intercept a transmission and reads it, they will not be able to re-transmit it to the intended receiver in exactly the same state that it was initially sent in. If this is attempted, then the intended receiver will receive meaningless data and it will obvious that someone has attempted to hack the communication.
The study comes from the Institute of Quantum Optics and Quantum Information at the Austrian Academy of Sciences (ÖAW) in Vienna. The research has been published in the journal Nature, with the paper titled “An entanglement-based wavelength-multiplexed quantum communication network.”
In further quantum news, researchers have discovered that a copper compound can serve as computing unit in quantum computers. Chemists at the Friedrich Schiller University of Jena have successfully synthesized a molecule that can take over the function of a computing unit in a quantum computer, thereby enhancing its efficiency.