  In a conventional quantum (k,n) threshold scheme, a trusted party shares a
secret quantum state with n participants such that any k of those participants
can cooperate to recover the original secret, while fewer than k participants
obtain no information about the secret. In this paper we show how to construct
a quantum (k,n) threshold scheme without the assistance of a trusted party, who
generates and distributes shares among the participants. Instead, each
participant chooses his private state and contributes the same to the
determination of the final secret quantum state.
