Disclosed is a method and system for transmitting data. The system includes at least one first stationary and/or mobile communication terminal at least one further second communication terminal and a switching unit reachable by all communication terminals via a data network. The communication terminals send data to the switching unit, which data are encrypted with a symmetric encryption method, and send the symmetric key encrypted with a public key of a key pair to the switching unit, so that the same can send it to other communication terminals, which in possession of an associated private key then are capable of accessing the information stored at the switching unit and decrypt the same.