Quantum Blockchain using entanglement in time

Understand

We propose a conceptual design for a quantum blockchain.

• Our method involves encoding the blockchain into a temporal GHZ (Greenberger-Horne-Zeilinger) state of photons that do not simultaneously coexist.
• It is shown that the entanglement in time, as opposed to an entanglement in space, provides the crucial quantum advantage.
• All the subcomponents of this system have already been shown to be experimentally realized.