The invention relates to a method for exchange of information between a computing unit of a first entity and a computing unit of at least one second entity. A computing unit of at least one second entity is detected and information on a token associated to the second entity from the computing unit is requested and received. On the basis of the received information, the token associated to the at least one second entity, is retrieved and a token associated to the first entity is modified at least partly with information of the received token associated to the at least one second entity. Finally, the modified token is utilized at least in the service the computing unit of the first entity belongs to. The invention relates also to a system and a computing unit implementing the method.