A method for secure communications in a telecommunications network is disclosed. The network comprises a group of servers Si, referred to as Authorization Servers. For a transaction between an entity A and an entity B of this method comprises: a) entity A sends to one of the Authorization Servers Si an authorization request; b) the entity A declares to the Authorization Server Si its intention to communicate with entity B and the Authorization Server Si determines an individual secret key KSiB which it shares with entity B; c) the Authorization Server Si generates a session key KN,SiAB and sends the session key KN,SiAB to entity A; d) the Authorization Server Si generates a transaction identifier IDTRN,Si; e) the authorization server Si supplies entity B the transaction identifier IDTRN,Si; f) using this transaction identifier IDTRN,Si, entity B checks the validity of the transaction, and g) entity B generates the session key KN,SiAB.