A theoretical scheme for multi-user quantum authentication and key distribution in a network is proposed. Similar to the authentication architecture of the netw ork in classical cryptography, a distributed client/server architecture with the shared Einstein-Podolsky-Rosen(EPR) entangled pairs between each user and his t rusted server used for the authentication and key distribution is proposed. Base d on this architecture, any-to-any multi-user quantum authentication and key dis tribution is realized. The trusted server only provides the authentication betwe en users and swaps the entanglement between the particles so as to entangle the particles of the two users who want to communicate secretly. The key generation is performed by the requesting user. Each user in a network only shares Einstein -Podolsky-Rosen entangled pairs with the trusted server and communicates with th e trusted server through the classical channel and quantum channel. Users need n ot share EPR entangled pairs with each other so that the number of EPR pairs in the network is reduced from O(n2) to O(n).