Secret Sharing with a Single d-level Quantum System
This provides a more scalable and technologically feasible solution for secure multiparty computation and key management in cryptography, though it is incremental as it simplifies existing quantum approaches.
The paper tackles the problem of secret sharing in cryptography by mapping quantum protocols that rely on multi-system entanglement into simpler ones using a single d-level quantum system, resulting in a protocol with huge scalability advantages that can be realized with current technology.
We give an example of a wide class of problems for which quantum information protocols based on multi-system entanglement can be mapped into much simpler ones involving one system. Secret sharing is a cryptographic primitive which plays a central role in various secure multiparty computation tasks and management of keys in cryptography. In secret sharing protocols, a classical message is divided into shares given to recipient parties in such a way that some number of parties need to collaborate in order to reconstruct the message. Quantum protocols for the task commonly rely on multi-partite GHZ entanglement. We present a multiparty secret sharing protocol which requires only sequential communication of a single quantum d-level system (for any prime d). It has huge advantages in scalabilility and can be realized with the state of the art technology. n be realized with the state of the art technology.