Patent ID: 7995603

Claim:
A method for securely multicasting media content to a plurality of end user devices without requiring one-to-one key exchange the method comprising: encrypting at least part of the media content with a key to form encrypted packets, the key being at least partially generable from key generation information, the key generation information and the key being changed according to a key period; multicasting the key generation information to the end user devices through an Internet Protocol packet-based network, the key generation information including first address information; multicasting the encrypted packets to the end user devices through the Internet Protocol packet-based network, the encrypted packets including second address information; creating an announcement including the second address information of the encrypted packets and the first address information of the key generation information; and transmitting the announcement to the end user devices wherein the end-user devices are operative to matching between the encrypted packets and the key generation information based on the first and second address information included in the announcement, wherein the transmitting and the multicasting takes place in the Internet Protocol packet-based network, the Internet Protocol packet-based network being secured according to an Internet protocol security standard, the announcement being created and transmitted according to an announcement protocol of the Internet protocol security standard.