A method and system are provided for securing telecommunications traffic data. A method is provided for transmitting messages via a telecommunications network between a number of subscribers by means of a telecommunications service, wherein the telecommunications service receives at least one first message of individual first size from at least one first subscriber to the telecommunications service that is intended for at least one second subscriber of the telecommunications service. In reaction to receiving a message, the telecommunications service sends at least one second message to the at least one second subscriber, wherein the at least one second message obtains a second size. The first size cannot be conclusively deduced from the second size.