Abstract. Multicast content delivery can be expected to become a major source of revenue with the increase of private broadband fixed and mobile communications. Several multicast applications require the receivers to securely send some real-time information back to the source, which leads to a many-to-one communication scenario. Using unicast connections to send this reverse traffic results in a data implosion which may swamp the source with incoming communication. In order to avoid this problem, a method for aggregating the information as it is being sent back to the source is presented in this paper. Confidentiality and authentication are guaranteed at the symbol level for this reverse realtime traffic.