A Headend system including a packer to pack media content into a plurality of packets including a first packet and a second packet, a packet scheduler to schedule when the packets will be broadcast/multicast to a plurality of end-user devices, and calculate a plurality of timing values including a first timing value which provides an indication of how long the second packet will arrive at the end-user devices after the arrival of the first packet at the end-user devices, and an encryption engine to: encrypt the media content of the packets and the timing values, wherein the media content of the first packet and the first timing value are encrypted by different encryption algorithms, or the same encryption algorithm with different cryptographic keys.