Editing Quantum Coin (section)

== Outline ==
In this scheme, a Trusted Third Party (TTP) and a coin holder run the following procedure for generating and verifying a quantum coin:<br>
* '''Quantum coin Generation''' - The TTP chooses k random 4-bit strings, keeps them in secret and produce k quantum states. A newly issued quantum coin consists of a piece of paper glued to k quantum registers that hold k quantum states. The piece of paper contains a unique identification tag and k initially unmarked positions, where the i-th position has to be marked in k-bit classical register P when the corresponding quantum state is used in the verification protocol.
* '''Quantum coin Verification''' - To verify a quantum coin through classical communication with the TTP, its holder sends the identification number of the quantum coin to the TTP. Then, the TTP and the coin holder exchange some classical information for choosing some quantum registers. The coin holder measures the chosen registers and sends their corresponding classical information to the TTP. The TTP verifies the authenticity of the coin by the secret information he possesses.