Patent ID: 7757089

Claim:
A content rendering method of rendering unified contents composed of a plurality of contents including at least first and second contents of web broadcasting, the method comprising: embedding a first digital watermark in the first content within a first time-offset, such that visible watermarks are embedded with key data in each scene of the first content individually and independently of each other scene; saving a first key in the second content enabling a removal of the first digital watermark; embedding a second digital watermark in the second content within a second time-offset; saving a second key in the second content enabling a removal of the second digital watermark; storing the first content and second content from web broadcasting on a computer server; setting viewable permission levels for each user wherein the viewable permission levels are set according to first and second viewable permission levels and a user level comprises first and second user levels wherein the first viewable permission level is viewable by the first user level and the second viewable permission level is viewable by the second user level; detecting the first key from the second content during the second time-offset and detecting the second key from the first content during the first time-offset; removing the first digital watermark based on the first key when the first key indicates the viewable permission level for the first content is the first viewable permission level, and removing the second digital watermark based on the second key when the second key indicates the viewable permission level for the first content is the second viewable permission level, and removing visible digital watermarks based on key data from invisible digital watermarks; and rendering the unified content, wherein the above steps are conducted using a computer while conducting web broadcasting.