Patent ID: 8645680

Claim:
A method of sending protected media data from a data source node to a client node via an intermediate node, the method comprising: at the media data source node, establishing a first hop-by-hop key to be shared with said intermediate node and an end-to-end key to be shared with said client node; configuring a single security protocol instance and using it to transform data relating to a media stream into transformed data using the end-to-end key and the first hop-by-hop key; sending the transformed media data to the intermediate node; at the intermediate node, using the established first hop-by-hop key to apply a first security processing to the transformed media data; at the intermediate node, establishing a second hop-by-hop key with the client node, and performing a second transformation on the transformed media data using the second hop-by-hop key to produce further transformed media data; at the intermediate node, sending the further transformed media data to the client node; at the client node, configuring a single security protocol instance with the second hop-by-hop key and the end-to-end key, and using the second hop-by-hop key to apply a second security processing to the received further transformed media data, and using the end-to-end key to apply a third security processing to the transformed media data.