公开(公告)号：DE60109467D1

公开(公告)日：2005-04-21

申请号：DE60109467

申请日：2001-09-19

Applicant: IBM

Inventor： CHANG YUAN-CHI ,  LI CHUNG-SHENG C O IBM UK LTD ,  HAN RICHARD ,  SMITH JOHN

IPC: G06F13/00 ,  G06F21/24 ,  H04L29/06 ,  H04N7/167 ,  H04N7/26 ,  H04N21/222 ,  H04N21/2343 ,  H04N21/2347 ,  H04N21/235 ,  H04N21/84

Abstract: A method and system enables network intermediaries such as proxies to transcode multimedia data without violating end-to-end security guarantees. In one embodiment, a content provider decomposes a data stream into a plurality of components, each of which are independently encrypted. In a preferred embodiment, an intermediary or proxy performs transcoding of the components by prioritizing and dropping predetermined components, in accordance with unencrypted clear-text metadata associated with each component, without the need for decrypting the components. Clear-text metadata preferably provides a semantic understanding of the absolute or relative importance/priority of the components with respect to each other, thereby facilitating the transcoding process. The destination/client device can subsequently decrypt the components transmitted by the transcoding proxy and reassemble them into a representation of the original data content.