A communication session management method for providing a transmission service having a plurality of service-levels, each service-level being associated with a separate quality-of-service (QOS), the method including preparing data for transmission at one of the plurality of service-levels by uniquely associating a service-level encryption key with the one of the plurality of service-levels, encrypting the data with the service-level encryption key to form encrypted data uniquely associated with the one of the plurality of service-levels, and transmitting the encrypted data uniquely associated with the one of the plurality of service-levels to users entitled to the one of the plurality of service-levels.