Ad-hoc mobile System is an infrastructure less System, i.e. there is no centralized coordination for the system operations. As and when a new node comes in the vicinity of the system it will spontaneously form the system. This paper presents a protected procedure for spontaneous mobile Ad-hoc system which uses a hybrid symmetric/asymmetric scheme and the trust between users in order to exchange the initial data and to exchange the secret keys that will be used to encrypt the data. The proposal is a complete self-configured protected procedure that is able to create the system and share protected services without any infrastructure.