The invention relates to processing, at a transmitting entity, messages to be transferred between a transmitting entity and a receiving entity. The method comprises: obtaining a message to be transferred to the receiving entity, defining a substantially unique identifier at least for one part of the message to be transferred, conditionally replacing said part of the message to be transferred with said substantially unique identifier, and forwarding the message for transfer to the receiving entity. Further the invention relates to processing, at a receiving entity, messages transferred between a transmitting entity and a receiving entity The method comprises: receiving a message transferred from the transmitting entity, the message comprising a substantially unique identifier as a substitute of a part of the message, and retrieving said substituted part of the message on the basis of said substantially unique identifier.