Method and system for customized audio and/or video content delivery

A content delivery network CDN configured for delivering watermarked audio and/or video streams of audio and/or video contents from a server equipment of the content delivery network CDN to a plurality of clients, the audio and/or video streams being segmented over time into segments, wherein the content delivery network CDN comprises electronics circuitry configured for:

• delivering common data segments via a multicast communication, common data segments being audio and/or video data segments intended to the plurality of clients;
• delivering customized data segments via unicast communications, customized data segments being watermarked audio and/or video data segments specifically intended for each client, the customized data segments thus including a watermark which is a hidden mark inside the audio and/or video content and which is specific to the identifier of said client or to information derived therefrom and such that each customized data segment includes only a portion of the watermark specific to the identifier of the client or the information derived therefrom;
• and
• building, for each client according to the identifier of the client in question or the information derived therefrom, one said watermarked audio and/or video stream from common data segments provided in multicast form by the server equipment and further including customized data segments provided in unicast form by the server equipment for customization to the client in question, wherein one or more customized data segments are interleaved between common data segments.