Abstract: Methods and system for providing content based on an embedded signal are disclosed. A method can comprise generating a placement signal based on an event, repeatedly embedding the placement signal into a data stream, and transmitting the data stream comprising the repeatedly embedded placement signal.

Abstract: Provided are a device and method for providing a video stream, in which a hash value of a frame is included in the header of a video stream, and authentication information about the header is inserted into the video stream, thus ensuring integrity against the forgery of the video stream. The device includes a base frame encoding unit which encodes a base frame, an enhancement frame encoding unit which encodes an enhancement frame, a frame encryption unit which encrypts the encoded base frame and the encoded enhancement frame, a hash processing unit which calculates hash values for the encrypted base frame and the encrypted enhancement frame and hash values included in headers of previous and subsequent video streams, a header management unit which includes information about the encoded base frame and the encoded enhancement frame and the calculated hash values, in a header, and manages the header, and an authentication information creation unit which creates authentication information about the header.