Siemens Aktiengesellschaft

Nokia Siemens Networks Gmbh & Co Kg

Srinath Thiruvengadam

Günther Horn

Wolfgang Bücker

Cryptographic material is generated for a protocol for the encrypted transmission of media data between a subscriber device and a provider device. A first symmetric key of the subscriber device and the provider device is inserted in a symmetric key protection mechanism of a network protocol of a control layer to establish a communication session between the subscriber device and the provider device. A first time-variable parameter is transmitted from the provider device to the subscriber device. A second symmetric key for protecting the key management protocol is calculated by both the provider device and the subscriber device using a defined function depending at least on the first symmetric key and the first time-variable parameter.

Method for providing a symmetric key for protecting a key management protocol

The invention relates to methods for encoding and decoding media data (MD, CMD). One of the methods comprises the following steps: A request is transmitted by a subscriber terminal () over a control network () to a control server () to establish a set of encoding parameters (K) for control data. The request includes identification data (ID) of the subscriber terminal (). The control server () thereupon specifies the set of encoding parameters (K) for control data, comprising a random number (R), a control data key (CK) and an integrity key (IK), wherein the control data key (CK) and the integrity key (IK) are dependent on the random number (R) and the identification data (ID). A media key (MK) dependent on the control data key (CK) and on the integrity key (IK) is then generated by the control server () and transmitted over a core network () to a media server (). The media key (MK) is used to encode and decode the media data (MD, CMD) subsequently transmitted over a media network (). The invention also relates to a subscriber terminal (), a control server (), and a computer program product that are suitable for implementing the method.

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Donauwörth, Germany

Srinath Thiruvengadam