Researchers at the University of the Witwatersrand in Johannesburg, South Africa, have demonstrated a record setting quantum protocol for sharing a secret amongst many parties.
The team created an 11-dimensional quantum state and used it to share a secret amongst 10 parties.
By using quantum tricks, the secret can only be unlocked if the parties trust one another.
The team used structured photons to reach high dimensions. Structured light means patterns of light and many patterns might be used to push the dimension limit. More dimensions mean more information in the light, and translates directly to larger secrets.
The work sets a new record for the dimension of the state (which impacts on how big the secret can be) and the number of parties with whom it is shared and is an important step towards distributing information securely across many nodes in a quantum network.
The paper has been published in Laser & Photonics Reviews.