multipartite entangled state, where a boss distributes a secret quantum state to two grades of
agents asymmetrically. The agents who belong to different grades have different authorities
for recovering the boss's secret. Except for the boss's Bell-state measurement, no nonlocal
operation is involved. The presented scheme is also shown to be secure against
eavesdropping. Such a hierarchical QIS is expected to find useful applications in the field of …