The invention relates to first information which is determined for a first receiver. Said first information is transmitted together with secondary information, which is determined for a second receiver in a common information unit to the first receiver. The first information can be encrypted according to specifications of the first receiver. The secondary information, which can be made of several components, is encrypted according to the specifications of the second receiver, for example, with an open key, a so-called public key. Said public key encryption methods have various embodiments and security steps. Said methods ensure that the first receiver, upon receipt of the complete information, can not encrypt pieces of information therefor not intended therefor.